JP2019016550A - Organic electroluminescent element, organic electroluminescent panel, organic electroluminescent device and electronic equipment - Google Patents

Abstract

An organic electroluminescent element capable of improving element performance, an organic electroluminescent panel including the organic electroluminescent element, an organic electroluminescent device, and an electronic apparatus are provided. An organic electroluminescent element according to an embodiment of the present disclosure includes an anode, an organic layer including a light emitting layer, and a cathode in this order. In the organic layer, the first organic layer between the light emitting layer and the anode includes a hole transport layer made of a material having an absorption coefficient of 0.1 or more and 0.6 or less. The light emitting layer has a light emission center at a position retreated from the anode side interface of the light emitting layer by a thickness larger than 0 and 0.4 or less when the thickness of the light emitting layer is 1. Yes. This organic electroluminescent element has a microcavity structure in which the position of the interface is a resonance point. [Selection] Figure 13

Description

  The present disclosure relates to an organic electroluminescent element, an organic electroluminescent panel, an organic electroluminescent device, and an electronic apparatus.

  Various types of organic electroluminescent devices (organic electroluminescent displays) using organic electroluminescent elements have been proposed (see, for example, Patent Document 1).

JP 2017-0772812 A

  By the way, in the organic electroluminescent device, generally, it is required to improve the element performance of the organic electroluminescent element. Therefore, it is desirable to provide an organic electroluminescent element capable of improving element performance, and an organic electroluminescent panel, an organic electroluminescent device, and an electronic apparatus provided with such an organic electroluminescent element.

  An organic electroluminescent element according to an embodiment of the present disclosure includes an anode, an organic layer including a light emitting layer, and a cathode in this order. In the organic layer, the first organic layer between the light emitting layer and the anode includes a hole transport layer made of a material having an absorption coefficient of 0.1 or more and 0.6 or less. The light emitting layer has a light emission center at a position retreated from the anode side interface of the light emitting layer by a thickness larger than 0 and 0.4 or less when the thickness of the light emitting layer is 1. Yes. This organic electroluminescent element has a microcavity structure in which the position of the interface is a resonance point.

  An organic electroluminescent panel according to an embodiment of the present disclosure includes a red pixel, a green pixel, and a blue pixel. Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescent element including an anode, an organic layer including a light emitting layer, and a cathode in this order. In the organic layer of at least one of the red pixel, the green pixel, and the blue pixel, the first organic layer between the light emitting layer and the anode is made of a material having an absorption coefficient of 0.1 to 0.6. A hole transport layer formed thereon. The light emitting layer in the pixel having the hole transport layer recedes from the anode side interface of the light emitting layer by a thickness greater than 0 and 0.4 or less when the thickness of the light emitting layer is 1. It has a light emission center at the position. The organic electroluminescent element in the pixel having the hole transport layer has a microcavity structure in which the position of the interface is a resonance point.

  An organic electroluminescent device according to an embodiment of the present disclosure includes an organic electroluminescent panel and a drive circuit that drives the organic electroluminescent panel. The organic electroluminescent panel provided in the organic electroluminescent device includes the same components as the above organic electroluminescent panel.

  An electronic apparatus according to an embodiment of the present disclosure includes an organic electroluminescent device. The organic electroluminescent device provided in the electronic apparatus includes the same components as the above organic electroluminescent device.

  In the organic electroluminescent element, the organic electroluminescent panel, the organic electroluminescent device, and the electronic device according to an embodiment of the present disclosure, the thickness of the luminescent layer is changed from the interface that is the place where the influence of quenching by the hole transport layer is the largest. A light emission center is a position which is set back by an amount greater than 0 and less than or equal to 0.4. Thereby, it is possible to suppress a decrease in strength due to deviation from the resonance point while avoiding the influence of quenching by the hole transport layer.

  According to the organic electroluminescent element, the organic electroluminescent panel, the organic electroluminescent device, and the electronic apparatus according to the embodiment of the present disclosure, the intensity caused by the deviation from the resonance point while avoiding the influence of quenching by the hole transport layer. As a result, the device performance of the organic electroluminescent device can be improved. In addition, the effect of this indication is not necessarily limited to the effect described here, Any effect described in this specification may be sufficient.

It is a figure showing the schematic structural example of the organic electroluminescent apparatus which concerns on one embodiment of this indication. FIG. 2 is a diagram illustrating a circuit configuration example of subpixels included in each pixel of FIG. 1. It is a figure showing the schematic structural example of the organic electroluminescent panel of FIG. It is a figure showing the cross-sectional structural example in the AA line of the organic electroluminescent panel of FIG. It is a figure showing the cross-sectional structural example in the BB line of the organic electroluminescent panel of FIG. It is a figure showing an example of the profile of the light emission area | region which generate | occur | produces in an organic light emitting layer. It is a figure showing an example of the profile of the light emission area | region which generate | occur | produces in an organic light emitting layer. It is a figure showing an example of the profile of the light emission area | region which generate | occur | produces in an organic light emitting layer. It is a figure showing an example of the profile of the light emission area | region which generate | occur | produces in an organic light emitting layer. It is a figure which represents typically the organic electroluminescent element of FIG. 4 for every subpixel. It is a figure showing an example of the film thickness of each layer in the organic electroluminescent element of FIG. It is a figure showing an example of the film thickness of each layer in the organic electroluminescent element which concerns on a comparative example. It is a figure showing an example of the relationship between the order of a cavity, and light extraction intensity | strength. It is a figure showing an example of the relationship between the order of a cavity, and light extraction intensity | strength. It is a figure showing an example of the intensity map of an organic electroluminescent element. It is a figure showing an example of the numerical value of the intensity | strength map of FIG. It is a figure showing an example of the relationship between the position of the light emission center in the organic electroluminescent element of FIG. 7, and light extraction intensity | strength. It is a figure showing an example of the relationship between the position of the light emission center in the organic electroluminescent element which concerns on a comparative example, and light extraction intensity | strength. It is a figure showing an example of the relationship between the absorption coefficient of a positive hole transport layer, and light extraction intensity | strength. It is a figure which represents perspectively an example of the appearance of electronic equipment provided with the organic electroluminescent device of this indication. It is a figure which represents perspectively an example of the external appearance of the illuminating device provided with the organic electroluminescent element of this indication.

  Hereinafter, modes for carrying out the present disclosure will be described in detail with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, component arrangement positions, connection forms, and the like shown in the following embodiments are merely examples and do not limit the present disclosure. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present disclosure are described as arbitrary constituent elements. Each figure is a schematic diagram and is not necessarily illustrated strictly. Moreover, in each figure, the same code | symbol is attached | subjected to the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

<1. Embodiment>
[Constitution]
FIG. 1 illustrates a schematic configuration example of an organic electroluminescent device 1 according to an embodiment of the present disclosure. FIG. 2 illustrates an example of a circuit configuration of the sub-pixel 12 included in each pixel 11 provided in the organic electroluminescence device 1. The organic electroluminescent device 1 includes, for example, an organic electroluminescent panel 10, a controller 20, and a driver 30. The driver 30 is mounted on the outer edge portion of the organic electroluminescent panel 10, for example. The organic electroluminescent panel 10 has a plurality of pixels 11 arranged in a matrix. The controller 20 and the driver 30 drive the organic electroluminescent panel 10 (the plurality of pixels 11) based on the video signal Din and the synchronization signal Tin input from the outside.

(Organic electroluminescent panel 10)
The organic electroluminescence panel 10 displays an image based on the video signal Din and the synchronization signal Tin inputted from the outside, by the active matrix driving of each pixel 11 by the controller 20 and the driver 30. The organic electroluminescence panel 10 includes a plurality of scanning lines WSL extending in the row direction, a plurality of signal lines DTL and a plurality of power supply lines DSL extending in the column direction, and a plurality of pixels 11 arranged in a matrix. have.

  The scanning line WSL is used for selecting each pixel 11, and supplies a selection pulse for selecting each pixel 11 for each predetermined unit (for example, a pixel row) to each pixel 11. The signal line DTL is used to supply a signal voltage Vsig corresponding to the video signal Din to each pixel 11 and supplies a data pulse including the signal voltage Vsig to each pixel 11. The power supply line DSL supplies power to each pixel 11.

  Each pixel 11 includes, for example, a sub-pixel 12 that emits red light, a sub-pixel 12 that emits green light, and a sub-pixel 12 that emits blue light. Note that each pixel 11 may further include, for example, a sub-pixel 12 that emits another color (for example, white or yellow). In each pixel 11, the plurality of subpixels 12 are arranged in a line in a predetermined direction, for example.

  Each signal line DTL is connected to an output terminal of a horizontal selector 31 described later. For example, one signal line DTL is assigned to each pixel column. Each scanning line WSL is connected to an output end of a write scanner 32 described later. For example, one scanning line WSL is assigned to each pixel row. Each power line DSL is connected to the output terminal of the power source. For example, one power line DSL is allocated to each pixel row.

  Each sub-pixel 12 includes a pixel circuit 12-1 and an organic electroluminescent element 12-2. The configuration of the organic electroluminescent element 12-2 will be described in detail later.

  The pixel circuit 12-1 controls light emission / extinction of the organic electroluminescent element 12-2. The pixel circuit 12-1 has a function of holding a voltage written in each sub-pixel 12 by writing scanning described later. The pixel circuit 12-1 includes, for example, a drive transistor Tr1, a write transistor Tr2, and a storage capacitor Cs.

  The write transistor Tr2 controls application of the signal voltage Vsig corresponding to the video signal Din to the gate of the drive transistor Tr1. Specifically, the write transistor Tr2 samples the voltage of the signal line DTL and writes the voltage obtained by the sampling to the gate of the drive transistor Tr1. The drive transistor Tr1 is connected in series with the organic electroluminescent element 12-2. The drive transistor Tr1 drives the organic electroluminescent element 12-2. The drive transistor Tr1 controls the current flowing through the organic electroluminescent element 12-2 according to the magnitude of the voltage sampled by the write transistor Tr2. The holding capacitor Cs holds a predetermined voltage between the gate and source of the driving transistor Tr1. The storage capacitor Cs has a role of holding the gate-source voltage Vgs of the drive transistor Tr1 constant during a predetermined period. The pixel circuit 12-1 may have a circuit configuration in which various capacitors and transistors are added to the above-described 2Tr1C circuit, or may have a circuit configuration different from the above-described 2Tr1C circuit configuration. Good.

  Each signal line DTL is connected to an output terminal of a horizontal selector 31 (to be described later) and a source or drain of the write transistor Tr2. Each scanning line WSL is connected to an output terminal of a later-described write scanner 32 and a gate of the write transistor Tr2. Each power line DSL is connected to the power circuit and the source or drain of the drive transistor Tr1.

  The gate of the writing transistor Tr2 is connected to the scanning line WSL. The source or drain of the write transistor Tr2 is connected to the signal line DTL. Of the source and drain of the write transistor Tr2, a terminal not connected to the signal line DTL is connected to the gate of the drive transistor Tr1. The source or drain of the drive transistor Tr1 is connected to the power supply line DSL. Of the source and drain of the driving transistor Tr1, a terminal not connected to the power supply line DSL is connected to the anode 21 of the organic electroluminescent element 21-2. One end of the storage capacitor Cs is connected to the gate of the drive transistor Tr1. The other end of the storage capacitor Cs is connected to a terminal on the organic electroluminescence element 21-2 side of the source and drain of the drive transistor Tr1.

(Driver 30)
The driver 30 includes, for example, a horizontal selector 31 and a write scanner 32. For example, the horizontal selector 31 applies the analog signal voltage Vsig input from the controller 20 to each signal line DTL in response to (in synchronization with) the input of the control signal. The write scanner 32 scans the plurality of subpixels 12 for each predetermined unit.

(Controller 20)
Next, the controller 20 will be described. For example, the controller 20 performs a predetermined correction on the digital video signal Din input from the outside, and generates a signal voltage Vsig based on the video signal obtained thereby. For example, the controller 20 outputs the generated signal voltage Vsig to the horizontal selector 31. For example, the controller 20 outputs a control signal to each circuit in the driver 30 in response to (in synchronization with) a synchronization signal Tin input from the outside.

  Next, the organic electroluminescent element 12-2 will be described with reference to FIG. 3, FIG. 4, and FIG. FIG. 3 shows a schematic configuration example of the organic electroluminescent panel 10. FIG. 4 illustrates an example of a cross-sectional configuration taken along line AA of the organic electroluminescent panel 10 of FIG. FIG. 5 illustrates a cross-sectional configuration example taken along line BB of the organic electroluminescent panel 10 of FIG.

  The organic electroluminescent panel 10 has a plurality of pixels 11 arranged in a matrix. For example, as described above, each pixel 11 includes a sub-pixel 12 (12R) that emits red light, a sub-pixel 12 (12G) that emits green light, and a sub-pixel 12 (12B) that emits blue light. ing. The sub-pixel 12R corresponds to a specific example of “red pixel” of the present disclosure. The sub-pixel 12G corresponds to a specific example of “green pixel” of the present disclosure. The sub-pixel 12B corresponds to a specific example of “blue pixel” of the present disclosure.

  The sub-pixel 12R includes an organic electroluminescent element 12-2 (12r) that emits red light. The subpixel 12G includes an organic electroluminescent element 12-2 (12g) that emits green light. The subpixel 12B includes an organic electroluminescent element 12-2 (12b) that emits blue light. The subpixels 12R, 12G, and 12B have, for example, a stripe arrangement. In each pixel 11, for example, sub-pixels 12R, 12G, and 12B are arranged side by side in the column direction. Furthermore, in each pixel row, for example, a plurality of subpixels 12 that emit light of the same color are arranged side by side in the row direction.

  The organic electroluminescent panel 10 has a plurality of line banks 13 extending in the row direction and a plurality of banks 15 extending in the column direction on the substrate 14. The plurality of line banks 13 and the plurality of banks 15 partition each sub-pixel 12R. The plurality of line banks 13 partitions each sub-pixel 12 in each pixel 11. The plurality of banks 15 partitions each pixel 11 in each pixel row. That is, the plurality of subpixels 12 are partitioned by a plurality of line banks 13 and a plurality of banks 15. Each bank 15 is provided between two line banks 13 adjacent to each other in the column direction. Both ends of each bank 15 are connected to two line banks 13 adjacent to each other in the column direction.

  The board | substrate 14 is comprised by the base material which supports each organic electroluminescent element 12-2, each line bank 13, etc., and the wiring layer provided on the base material, for example. The base material in the substrate 14 is formed of, for example, alkali-free glass, soda glass, non-fluorescent glass, phosphate glass, borate glass, or quartz. The base material in the substrate 14 may be formed of, for example, an acrylic resin, a styrene resin, a polycarbonate resin, an epoxy resin, polyethylene, polyester, a silicone resin, or alumina. For example, a pixel circuit 12-1 of each pixel 11 is formed in the wiring layer in the substrate 14.

  The line bank 13 and the bank 15 are made of, for example, an insulating organic material. Examples of the insulating organic material include acrylic resin, polyimide resin, and novolac type phenol resin. For example, the line bank 13 and the bank 15 are preferably formed of an insulating resin having heat resistance and resistance to a solvent. The line bank 13 and the bank 15 are formed, for example, by processing an insulating resin into a desired pattern by photolithography and development. The cross-sectional shape of the line bank 13 may be, for example, a forward taper type as shown in FIG. 4 or a reverse taper type with a narrow skirt.

  A region surrounded by two line banks 13 and banks 15 at both ends that are parallel to each other and adjacent to each other is a groove 16. In each sub-pixel 12, each organic electroluminescence element 12-2 is arranged one by one in the gap between two line banks 13 that are parallel to each other and adjacent to each other. That is, in each sub-pixel 12, each organic electroluminescent element 12-2 is arranged one by one in the groove 16.

  Each organic electroluminescent element 12-2 includes, for example, an anode 21, a hole injection layer 22, a hole transport layer 23, an organic light emitting layer 24, an electron transport layer 25, an electron injection layer 26, and a cathode 27 from the substrate 14 side. It is prepared in order. Of the hole injection layer 22 and the hole transport layer 23, at least the hole transport layer 23 corresponds to a specific example of a “first organic layer” of the present disclosure. The organic light emitting layer 24 corresponds to a specific example of “light emitting layer” of the present disclosure. Of the electron transport layer 25 and the electron injection layer 26, at least the electron transport layer 25 corresponds to a specific example of a “second organic layer” of the present disclosure. The hole injection layer 22 is a layer for increasing the hole injection efficiency. The hole transport layer 23 is a layer for transporting holes injected from the anode 21 to the organic light emitting layer 24. The organic light emitting layer 24 is a layer that emits light of a predetermined color by recombination of electrons and holes. The electron transport layer 25 is a layer for transporting electrons injected from the cathode 27 to the organic light emitting layer 24. The electron injection layer 26 is a layer for increasing electron injection efficiency. At least one of the hole injection layer 22 and the electron injection layer 26 may be omitted. Each organic electroluminescent element 12-2 may further include layers other than those described above.

  The anode 21 is formed on the substrate 14, for example. The anode 21 is a transparent electrode having translucency. For example, a transparent conductive film made of a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) is used. The anode 21 is not limited to a transparent electrode, and may be, for example, aluminum (Al), silver (Ag), aluminum or a silver alloy, or a reflective electrode having reflectivity. The anode 21 may be a laminate of a reflective electrode and a transparent electrode.

  The hole transport layer 23 has a function of transporting holes injected from the anode 21 to the organic light emitting layer 24. The hole transport layer 23 is, for example, a coating film. The hole transport layer 23 is formed, for example, by applying and drying a solution containing an organic material having a hole transport property (hereinafter referred to as “hole transport material 23M”) as a main component of a solute. Yes. The hole transport layer 23 includes a hole transport material 23M as a main component. Moreover, the hole transport material 12M which is a solute has a function of insolubilizing. The insolubilizing function refers to a function in which an insolubilizing group such as a crosslinkable group or a heat dissociable soluble group undergoes a chemical change by irradiation with heat or ultraviolet light or a combination thereof, and insolubilizes in an organic solvent or water. Therefore, the hole transport layer 12 is an insolubilized hole transport layer.

  The hole transporting material 23M that is a raw material (material) of the hole transporting layer 23 includes, for example, arylamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine Derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, butadiene compounds, polystyrene derivatives, hydrazone derivatives, triphenylmethane derivatives, tetraphenylbenzine derivatives, etc., or a combination thereof Material. The hole transporting material 23M further includes, for example, a soluble group and an insolubilizing group such as a thermally dissociable soluble group, a crosslinkable group, or a removable protective group in the molecular structure for the function of solubility and insolubilization. And have.

  The organic light emitting layer 24 has a function of emitting light of a predetermined color by recombination of holes and electrons. The organic light emitting layer 24 is, for example, a coating film. The organic light-emitting layer 24 is formed by applying and drying a solution containing an organic material that emits light by generating excitons by recombination of holes and electrons (hereinafter, referred to as “organic light-emitting material 24M”). Is formed. The organic light emitting layer 24 includes an organic light emitting material 24M as a main component. In the organic electroluminescent element 12r included in the sub-pixel 12R, the organic light emitting material 24M includes a red organic light emitting material. In the organic electroluminescent element 12g included in the sub-pixel 12G, the organic light emitting material 24M includes a green organic light emitting material. In the organic electroluminescent element 12b included in the sub-pixel 12B, the organic light emitting material 24M includes a blue organic light emitting material.

  The organic light emitting layer 24 is constituted by, for example, a single organic light emitting layer or a plurality of stacked organic light emitting layers. In the case where the organic light emitting layer 24 is constituted by a plurality of organic light emitting layers stacked, the organic light emitting layer 24 is formed by stacking a plurality of organic light emitting layers whose main components are common to each other, for example. At this time, the plurality of organic light emitting layers are all coating films. Both of the plurality of organic light emitting layers are formed by applying and drying a solution containing the organic light emitting material 24M as a main component of a solute.

  The organic light emitting material 24M that is a raw material (material) of the organic light emitting layer 24 may be, for example, a dopant material alone, but more preferably a combination of a host material and a dopant material. That is, the organic light emitting layer 24 is preferably configured to include a host material and a dopant material as the organic light emitting material 24M. The host material mainly has the function of transporting electrons or holes, and the dopant material has the function of light emission. The host material and the dopant material are not limited to one type, and may be a combination of two or more types. The amount of the dopant material is preferably 0.01% by weight to 30% by weight and more preferably 0.01% by weight to 10% by weight with respect to the host material.

  As a host material of the organic light emitting layer 24, for example, an amine compound, a condensed polycyclic aromatic compound, or a heterocyclic compound is used. As the amine compound, for example, a monoamine derivative, a diamine derivative, a triamine derivative, or a tetraamine derivative is used. Examples of the condensed polycyclic aromatic compound include anthracene derivatives, naphthalene derivatives, naphthacene derivatives, phenanthrene derivatives, chrysene derivatives, fluoranthene derivatives, triphenylene derivatives, pentacene derivatives, and perylene derivatives. Examples of heterocyclic compounds include carbazole derivatives, furan derivatives, pyridine derivatives, pyrimidine derivatives, triazine derivatives, imidazole derivatives, pyrazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, pyrrole derivatives, indole derivatives, azaindole derivatives, Azacarbazole, a pyrazoline derivative, a pyrazolone derivative, a phthalocyanine derivative, or the like can be given.

  Moreover, as a dopant material of the organic light emitting layer 24, a pyrene derivative, a fluoranthene derivative, an aryl acetylene derivative, a fluorene derivative, a perylene derivative, an oxadiazole derivative, an anthracene derivative, or a chrysene derivative is used, for example. In addition, a metal complex may be used as a dopant material for the organic light emitting layer 24. Examples of the metal complex include a metal atom and a ligand such as iridium (Ir), platinum (Pt), osmium (Os), gold (Au), rhenium (Re), or ruthenium (Ru). Is mentioned.

  In the organic electroluminescent element 12r included in the sub-pixel 12R, the organic light emitting material 24M is made of an organic light emitting material whose electron mobility is larger than the hole mobility. That is, the organic light emitting material 24M included in the organic electroluminescent element 12r is a material having a high electron transport property and a material having an electron mobility larger than the hole mobility. Therefore, in the organic electroluminescent element 12r, the light emitting region 12A is located on the hole transport layer 23 side. In the organic electroluminescent element 12r, the light emitting region 12A may be positioned near the interface with the hole transport layer 23.

  In the organic electroluminescent element 12g included in the subpixel 12G, the organic light emitting material 24M is made of an organic light emitting material having an electron mobility larger than the hole mobility. That is, the organic light emitting material 24M included in the organic electroluminescent element 12g is a material having a high electron transport property and a material having an electron mobility larger than the hole mobility. Therefore, in the organic electroluminescent element 12g, the light emitting region 12A is located on the hole transport layer 23 side. In the organic electroluminescent element 12g, the light emitting region 12A may be located in the vicinity of the interface with the hole transport layer 23.

  In the organic electroluminescent element 12g included in the subpixel 12B, the organic light emitting material 24M is made of an organic light emitting material having a hole mobility larger than the electron mobility. That is, the organic light emitting material 24M included in the organic electroluminescent element 12b is a material having a high hole transport property and a material having an electron mobility larger than the hole mobility. Therefore, in the organic electroluminescent element 12b, the light emitting region 12A is located on the electron transport layer 25 side. In the organic electroluminescent element 12b, the light emitting region 12A may be located in the vicinity of the interface with the electron transport layer 25.

  “The light emitting region 12A is located on the electron transport layer 25 side” means that, for example, as shown in FIG. 6A, 50% or more of the light emitting region 12A in the organic light emitting layer 24 is disposed in the electron transport layer 25. It is present in the area on the other side. “The light emitting region is located on the hole transport layer 23 side” means that, for example, as shown in FIG. 6B, 50% or more of the light emitting region 12A in the organic light emitting layer 24 is disposed in the hole transport layer 23. Indicates that it exists in the side area.

  “The light emitting region 12A is located near the interface with the electron transport layer 25” means that, for example, 90% or more of the light emitting region 12A in the organic light emitting layer 24 is 90% or more as shown in FIG. It means that it exists on the side where it is placed. “The light emitting region 12A is positioned in the vicinity of the interface with the hole transport layer 23” means that, for example, 90% or more of the light emitting region 12A in the organic light emitting layer 24 is 90% or more as shown in FIG. 23 exists in the area | region where the side is arrange | positioned. 6A to 6D show an example of the light emitting region 12A. For example, the peak of the light emitting region (the light emission center 12a) may be located in the organic light emitting layer 24 instead of the interface of the organic light emitting layer 24. As a method of changing the profile of the light emitting region 12A and the position of the peak (light emission center 12a), for example, there is a method of adjusting the ratio of the host material and the dopant material contained in the organic light emitting layer 24.

  The electron transport layer 25 has a function of transporting electrons injected from the cathode 27 to the organic light emitting layer 24. The electron transport layer 25 is, for example, a deposited film or a sputtered film. The electron transport layer 25 includes an organic material having an electron transport property (hereinafter, referred to as “electron transport material 25M”) as a main component. The electron transport layer 25 is preferably made of an organic material having a wide energy gap that is suitable for preventing hole blocking and exciton deactivation. The electron transport layer 25 is made of an organic material in which the energy gap of the electron transport layer 25 is larger than the energy gap of the organic light emitting layer 24.

  The energy gap refers to an energy difference between a HOMO (highest occupied molecular orbital) energy level and a LUMO (lowest unoccupied molecular orbital) energy level. The energy gap is also called a band gap. Examples of the method for measuring the HOMO level include atmospheric photoelectron spectroscopy, electrochemical techniques (cyclic voltammetry), and photoelectron spectroscopy (PES). On the other hand, examples of the LUMO level measurement method include inverse photoelectron spectroscopy (IPES), a method of calculating from the energy gap obtained from the absorption edge by light absorption spectroscopy and the HOMO level. In addition, a method of calculating the HOMO level and the LUMO level rank for each level using molecular activation method calculation may be used.

  The electron transport layer 25 is interposed between the organic light emitting layer 24 and the cathode 27 and has a function of transporting electrons injected from the cathode 27 to the organic light emitting layer 24. The electron transport layer 25 further suppresses charge blocking function that suppresses the penetration of charges (holes in the present embodiment) from the organic light emitting layer 24 to the cathode 27 and quenching of the excited state of the organic light emitting layer 24. It is preferable to have the function to perform. The electron transporting material 25M that is a raw material (material) of the electron transporting layer 25 is, for example, an aromatic heterocyclic compound containing one or more heteroatoms in the molecule. Examples of the aromatic heterocyclic compound include compounds containing a pyridine ring, a pyrimidine ring, a triazine ring, a benzimidazole ring, a phenanthroline ring, a quinazoline ring or the like in the skeleton. Further, the electron transport layer 25 may include a metal having an electron transport property. The electron transport layer 25 can improve the electron transport property of the electron transport layer 25 by containing the metal which has electron transport property. Examples of the metal contained in the electron transport layer 25 include barium (Ba), lithium (Li), calcium (Ca), potassium (K), cesium (Cs), sodium (Na), rubidium (Rb), yttrium ( Yb) or the like can be used.

  The cathode 27 is, for example, a reflective electrode having light reflectivity, and is, for example, a metal electrode formed using a metal material having reflectivity. As the material of the cathode 27, for example, aluminum (Al), magnesium (Mg), silver (Ag), aluminum-lithium alloy, magnesium-silver alloy, or the like is used. The cathode 27 is not limited to the reflective electrode, and may be a transparent electrode such as an ITO film, like the anode 21. When the substrate 14 and the anode 21 are translucent and the cathode 27 is reflective, the organic electroluminescent element 12-2 has a bottom emission structure in which light is emitted from the substrate 14 side. When the anode 21 has reflectivity and the cathode 27 has translucency, the organic electroluminescent element 12-2 has a top emission structure.

  The organic electroluminescent panel 10 may further include, for example, a sealing layer 28 that seals each organic electroluminescent element 12-2. The sealing layer 28 is provided in contact with the surface of the cathode 27 of each organic electroluminescent element 12-2, for example.

  Next, the characteristics of the organic electroluminescent element 12-2 according to the present embodiment will be described with a comparative example. FIG. 7 schematically shows the organic electroluminescent element 12-2 for each type of subpixel 12. FIG. 8 shows an example of the film thickness of each layer in the organic electroluminescent element 12-2 of FIG. FIG. 9 shows an example of the film thickness of each layer in the organic electroluminescent element according to the comparative example. 10 and 11 show an example of the relationship between the order of the cavity and the light extraction intensity. FIG. 12 shows an example of an intensity map of the organic electroluminescent element 12-2. FIG. 12A shows an example of an intensity map of the organic electroluminescent element 12-2 of the red subpixel 12R. FIG. 12B shows an example of an intensity map of the organic electroluminescent element 12-2 of the green sub-pixel 12R. FIG. 12C shows an example of an intensity map of the organic electroluminescent element 12-2 of the blue subpixel 12R. FIG. 13 shows an example of numerical values of the intensity map of FIG.

  In the subpixel 12R, the subpixel 12G, and the subpixel 12B, the organic electroluminescent element 12-2 has a microcavity structure. The left end of FIG. 7 illustrates a microcavity structure Cr provided in the organic electroluminescent element 12-2 of the subpixel 12R. In the center of FIG. 7, a microcavity structure Cg provided in the organic electroluminescent element 12-2 of the sub-pixel 12G is illustrated. In the microcavity structure Cr, Cg in FIG. 7, the layer formed of the hole injection layer 22 and the hole transport layer 23 corresponds to a specific example of “first organic layer” of the present disclosure. In the microcavity structures Cr and Cg in FIG. 7, the layer including the electron transport layer 25 and the electron injection layer 26 corresponds to a specific example of “second organic layer” of the present disclosure. In FIG. 7, the hole injection layer 22 may be omitted. In FIG. 7, the electron injection layer 26 may be omitted. Further, in the microcavity structure Cr, Cg of FIG. 7, when the whole or part of the hole injection layer 22 is made of an inorganic material, the layer composed of the hole injection layer 22 and the hole transport layer 23 Of these, a portion made of an organic material corresponds to a specific example of the “first organic layer” of the present disclosure. The right end of FIG. 7 illustrates a microcavity structure Cb provided in the organic electroluminescent element 12-2 of the subpixel 12B. The microcavity structures Cr, Cg, and Cb have an effect of enhancing light of a specific wavelength by utilizing resonance of light generated between the anode 21 and the cathode 27, for example. The light emitted from the organic light emitting layer 24 undergoes multiple reflections between the anode 21 and the cathode 27. At this time, a specific wavelength component of the light emitted from the organic light emitting layer 24 is strengthened.

  In the present embodiment, the wavelengths of light emitted from the subpixel 12R, the subpixel 12G, and the subpixel 12B are different. Therefore, the optical path length between the anode 21 and the cathode 27 corresponds to the emission spectrum peak wavelength of each color. The light emitted from the organic light emitting layer 24 by the microcavity structure Cr, Cg, Cb is repeatedly reflected within a predetermined optical length range between the anode 21 and the cathode 27, and has a specific wavelength corresponding to the optical path length. While the light of this wavelength is resonated and enhanced, the light of a wavelength not corresponding to the optical path length is attenuated. As a result, the spectrum of the light extracted to the outside becomes steep and high intensity, and the luminance and color purity are improved.

  In the microcavity structure, as the film thickness increases, primary interference (first cavity), secondary interference (second cavity), tertiary interference (third cavity), and the like are generated. The microcavity structures Cr and Cg have an optical path length in which a second cavity is generated. On the other hand, the microcavity structure Cb has an optical path length in which a third cavity is generated. In the microcavity structure Cr, the distance Lr between the anode 21 and the cathode 27 is an optical path length in which a second cavity is generated at the wavelength of light (red light) emitted from the organic light emitting layer 24 of the subpixel 12R. In the microcavity structure Cg, the distance Lg between the anode 21 and the cathode 27 is an optical path length in which a second cavity is generated at the wavelength of light (green light) emitted from the organic light emitting layer 24 of the subpixel 12G. Yes. In the microcavity structure Cb, the distance Lg between the anode 21 and the cathode 27 is an optical path length in which a third cavity is generated at the wavelength of light (blue light) emitted from the organic light emitting layer 24 of the subpixel 12B. Yes.

  In the present embodiment, in the subpixel 12R, the subpixel 12G, and the subpixel 12B, the electron transport layer 25 is configured by a common layer. For example, in the sub-pixel 12R, the sub-pixel 12G, and the sub-pixel 12B, the electron transport layer 25 is collectively formed by vapor deposition or sputtering. In the subpixel 12R and the subpixel 12G, the hole injection layer 22, the hole transport layer 23, the organic light emitting layer 24, the electron transport layer 25, and the electron injection layer 26 are distances Lr, Lg between the anode 21 and the cathode 27, respectively. However, the film thickness is adjusted so as to be the optical path length in which the second cavity is generated. In the subpixel 12B, the hole injection layer 22, the hole transport layer 23, the organic light emitting layer 24, the electron transport layer 25, and the electron injection layer 26 have a distance Lb between the anode 21 and the cathode 27 that is equal to the third cavity. The film thickness is adjusted to be the optical path length that causes

  In designing an organic electroluminescent element, the distance between the anode 21 and the light emission center 24a and the distance between the cathode 27 and the light emission center 24a are very important. Strictly speaking, the reference points of these distances are positions where luminescence recombination occurs.

  In FIG. 8, in the subpixel 12R and the subpixel 12G, the emission center 24a is located on the hole transport layer 23 side in the organic light emitting layer 24, and in the subpixel 12B, the emission center 24a is transported in the organic light emitting layer 24. An example of the film thickness of each layer when located on the layer 25 side is shown. In FIG. 8, the unit of film thickness is nm. In the upper part of FIG. 8, in the microcavity structure Cr, an ideal film thickness of a portion (upper layer) corresponding to the upper portion of the light emission center 24a and an ideal film thickness of a portion (lower layer) corresponding to the lower portion of the light emission center 24a. The film thickness is exemplified.

  In the sub-pixel 12R, the upper layer thickness Lr1 is ideally 250 nm, and the lower layer thickness Lr2 is ideally 60 nm. The film thickness Lr1 corresponds to a specific example of “second distance” of the present disclosure, and the film thickness Lr2 corresponds to a specific example of “first distance” of the present disclosure. The film thicknesses Lr1 and Lr2 have optical path lengths such that the light emitted from the light emission center 24a resonates with the microcavity structure Cr. In the sub-pixel 12G, the film thickness Lg1 of the upper layer is ideally 215 nm, and the film thickness Lg2 of the lower layer is ideally 50 nm. The film thicknesses Lg1 and Lg2 have optical path lengths such that light emitted from the light emission center 24a resonates with the microcavity structure Cg. The film thickness Lg1 corresponds to a specific example of “second distance” of the present disclosure, and the film thickness Lg2 corresponds to a specific example of “first distance” of the present disclosure. In the sub-pixel 12B, the upper layer thickness Lb1 is ideally 170 nm, and the lower layer thickness Lb2 is ideally 180 nm. The film thicknesses Lb1 and Lb2 have optical path lengths such that light emitted from the light emission center 24a resonates with the microcavity structure Cb.

  Moreover, the film thickness of each layer contained in the organic electroluminescent element 12-2 is illustrated by the lower stage of FIG. In each subpixel 12, the electron transport layer 25 and the electron injection layer 24 are collectively formed by vapor deposition or sputtering, and the total film thickness of the electron transport layer 25 and the electron injection layer 24 is 170 nm. . In the subpixel 12r, the thickness of the organic light emitting layer 24 is 80 nm, and the total thickness of the hole transport layer 23 and the hole injection layer 22 is 60 nm. In the subpixel 12g, the thickness of the organic light emitting layer 24 is 45 nm, and the total thickness of the hole transport layer 23 and the hole injection layer 22 is 50 nm. In the subpixel 12b, the thickness of the organic light emitting layer 24 is 50 nm, and the total thickness of the hole transport layer 23 and the hole injection layer 22 is 130 nm.

  From FIG. 8, in each subpixel 12, the film thickness of the organic light emitting layer 24 is a film thickness (45 nm to 80 nm) suitable for coating, and the total film of the hole transport layer 23 and the hole injection layer 22 It can be seen that the thickness is also suitable for coating (50 nm to 130 nm).

  FIG. 9 illustrates the film thickness in each sub-pixel according to the comparative example. FIG. 9 shows an example of the film thickness of each layer when the emission center is located on the side of the hole transport layer in the organic light emitting layer in each color subpixel. In FIG. 9, the unit of film thickness is nm. In the upper part of FIG. 9, in the microcavity structure of each color sub-pixel, an ideal film thickness of a portion (upper layer) corresponding to the upper portion of the light emission center and a portion (lower layer) corresponding to the lower portion of the light emission center are shown. The ideal film thickness is illustrated. Moreover, the film thickness of each layer contained in an organic electroluminescent element is illustrated by the lower stage of FIG. In FIG. 9, the total film thickness of the hole transport layer 23 and the hole injection layer 22 in the blue subpixel is thicker than the film thickness suitable for coating. Therefore, it can be seen that in the blue subpixel, it is inappropriate from the viewpoint of coating to dispose the emission center on the hole transport layer side in the organic light emitting layer.

  By the way, when determining the order of the cavity in the microcavity structure, only the interference effect has been considered in the conventional simulation. Therefore, as shown in FIG. 10, it can be seen that the light extraction efficiency decreases significantly as the order of the cavity increases. Therefore, from the viewpoint of light extraction efficiency, it is understood that the order of the cavity is preferably the first order and that the second order or the third order is not preferable. On the other hand, the inventors of the present application have found that not only the interference effect but also metal quenching should be considered in order to determine the order of the cavity in the microcavity structure. Therefore, the inventors of the present application derived the relationship between the light extraction efficiency and the order of the cavities in the microcavity structure through a simulation that takes into account interference effects and metal quenching. The results are shown in FIG. From FIG. 11, it can be seen that in the subpixel 12R and the subpixel 12G, the order of the cavity is preferably set to the second order rather than the first order. Furthermore, it can be seen from FIG. 11 that in the sub-pixel 12B, the order of the cavity is preferably 3 order rather than 1 order. In the sub-pixel 12B, the light extraction efficiency when the cavity order is second order is smaller than the light extraction efficiency when the cavity order is third order. This seems to be because the distance is longer than that of the sub-pixels 12R and 12G.

  In FIGS. 12A, 12B, and 12C, an intensity map (the magnitude of light extraction efficiency is shown) when the horizontal axis is the thickness of the lower layer and the vertical axis is the thickness of the upper layer. Map) is shown. FIG. 13 shows the ratio of the peak value in each order when the maximum value in the light extraction efficiency shown in FIGS. 12 (A), 12 (B), and 12 (C) is 100%. Yes.

  12A, 12B, and 12C, it can be seen that there are two secondary cavities. In addition, it can be seen that there are three tertiary cavities in FIGS. 12A, 12B, and 12C. From FIG. 12A, FIG. 12B, and FIG. 12C, when the lower layer is thinner and the upper layer is thicker, the lower layer is thicker and the upper layer is thicker. It can be seen that the light extraction efficiency in the secondary cavity is higher than when the film thickness is reduced. Also, from FIGS. 12A, 12B, and 12C, when the thickness of the lower layer is the second smallest and the thickness of the upper layer is the second smallest, It can be seen that the light extraction efficiency is the highest. Further, when the light extraction efficiency in the secondary cavity and the light extraction efficiency in the tertiary cavity are compared, in the subpixel 12R and the subpixel 12G, the light extraction efficiency in the secondary cavity is the third order. It can be seen that the light extraction efficiency in the cavity is higher. On the other hand, in the sub-pixel 12B, it can be seen that the light extraction efficiency in the tertiary cavity is higher than the light extraction efficiency in the secondary cavity.

  From the above, the microcavity structures Cr and Cg preferably have an optical path length in which a second cavity is generated from the viewpoint of light extraction efficiency. On the other hand, it is preferable that the microcavity structure Cb has an optical path length in which a third cavity is generated from the viewpoint of light extraction efficiency.

  FIG. 14 illustrates an example of the relationship between the position of the light emission center 12a and the light extraction intensity in the organic electroluminescent element 12-2 according to the present embodiment. FIG. 15 shows an example of the relationship between the order of the cavity and the light extraction intensity in the organic electroluminescent element according to the comparative example. FIG. 16 shows an example of the relationship between the absorption coefficient k of the hole transport layer 23 and the light extraction intensity. The absorption coefficient k can be derived using, for example, a spectroscopic ellipsometer that can handle thin films of several tens to several hundreds of nanometers.

  FIG. 14 shows an example of the relationship between the light extraction intensity and the position of the emission center 12a of the subpixel 12R and subpixel 12G when the absorption coefficient k of the hole transport layer 23 in contact with the organic light emitting layer 24 is 0.06. It is shown. FIG. 15 shows an example of the relationship between the position of the emission center 12a of the subpixel 12R and the subpixel 12G and the light extraction intensity when the absorption coefficient k of the hole transport layer 23 in contact with the organic light emitting layer 24 is zero. ing. 14 and 15, the resonance point of the microcavity structures Cr and Cg is the position of the interface of the organic light emitting layer 24 (specifically, the interface between the organic light emitting layer 24 and the hole transport layer 23). . FIG. 16 illustrates the relationship between the absorption coefficient k of the hole transport layer 23 and the light extraction intensity at the interface between the organic light emitting layer 24 and the hole transport layer 23 in the subpixel 12R and the subpixel 12G. .

  By the way, the absorption coefficient k of the hole transport layer 23 is not actually zero and can take various values depending on the material. Of the subpixel 12R and the subpixel 12G, the hole transport layer 23 of at least one of the subpixels 12 is generally made of a material having an absorption coefficient k of 0.1 or more and 0.6 or less. Therefore, when the emission center 12 a is at the interface between the organic light emitting layer 24 and the hole transport layer 23, a loss occurs in the near-field energy of light emission due to the absorption coefficient k of the hole transport layer 23. As a result, the light extraction efficiency may be reduced.

  Therefore, in the organic electroluminescent element 12-2 according to the present embodiment, the organic light emitting layer 24 of the subpixel 12 having the hole transport layer 23 made of a material having an absorption coefficient k of 0.1 or more and 0.6 or less. For example, as shown in FIG. 14, from the interface of the organic light emitting layer 24 on the hole transport layer 23 side, the thickness of the organic light emitting layer 24 is larger than 0 and 0.4 or less. A light emission center 12a (first light emission center) is provided at a position retreated by the thickness of. As a result, the light extraction efficiency is improved as compared with the case where the emission center 12 a is at the interface between the organic light emitting layer 24 and the hole transport layer 23. Further, the organic light emitting layer 24 of the sub-pixel 12 having the hole transport layer 23 made of a material having an absorption coefficient k of 0.1 or more and 0.6 or less is, for example, as shown in FIG. The emission center 12a (in the position where the thickness of the organic light emitting layer 24 is set back from the interface of the layer 24 on the hole transport layer 23 side by a thickness of 0.1 to 0.2 when the thickness of the organic light emitting layer 24 is 1. More preferably, it has a first emission center. In this case, the light extraction efficiency is most improved.

  In FIG. 16, when the absorption coefficient k of the hole transport layer 23 is gradually increased from 0, the light extraction intensity at the interface between the organic light emitting layer 24 and the hole transport layer 23 gradually decreases. Is shown (black circle in the figure). This is because the near-field energy of light emission is lost due to the absorption coefficient k of the hole transport layer 23. On the other hand, the portion where the light extraction intensity is maximum (white circle in the figure) is 0 from the interface between the organic light emitting layer 24 and the hole transport layer 23 when the thickness of the organic light emitting layer 24 is 1. .Retracted by the thickness of 1 or more and 0.2 or less. Thus, it can be seen that the light extraction intensity can be maximized by disposing the emission center 12a at a position slightly away from the interface (that is, the resonance point) between the organic light emitting layer 24 and the hole transport layer 23. .

[effect]
Next, the effect of the organic electroluminescent panel 10 of this Embodiment and the organic electroluminescent apparatus 1 provided with the same is demonstrated.

  Conventionally, many attempts have been made to improve the light extraction efficiency of an organic electroluminescent device. This is because power consumption can be reduced by increasing the light extraction efficiency. It is conceivable to use the microcavity effect as one means for increasing the light extraction efficiency. However, as shown in FIG. 9, in the optical calculation considering only the interference effect, if a second-order or higher cavity is used, the light extraction efficiency is rather lowered.

  On the other hand, in the present embodiment, each of the microcavity structures of the red pixel 12R and the green pixel 12G has an optical path length in which a second cavity is generated. On the other hand, the microcavity structure of the blue pixel 12B has an optical path length in which a third cavity is generated. This is because in the optical calculation considering not only the interference effect but also the metal quenching effect, the light extraction efficiency depends on not only the interference effect but also the metal quenching effect as shown in FIG. According to FIG. 10, in the red pixel 12R and the green pixel 12G, the light extraction efficiency is maximized when the secondary cavity is used, and in the blue pixel 12B, the light extraction efficiency is maximized when the tertiary cavity is used. It becomes. Therefore, the microcavity structure of the red pixel 12R and the green pixel 12G is configured so as to have the optical path length (resonator length) in which the second cavity is generated, and the optical path length (resonator length) in which the third cavity is generated. By configuring the microcavity structure of the blue pixel 12B, not only the interference effect but also the influence of metal quenching can be mitigated, and the light extraction efficiency can be improved. As a result, the element performance of the organic electroluminescent element 12-2 can be improved.

  In the present embodiment, in the sub-pixel 12R and the sub-pixel 12G, the distances Lr and Lg between the anode 21 and the cathode 27 are optical path lengths in which a second cavity is generated. That is, the hole injection layer 22, the hole transport layer 23, the organic light emitting layer 24, the electron transport layer 25, and the electron injection layer 26 are the distance Lr between the anode 21 and the cathode 27 in the subpixel 12R and the subpixel 12G. , Lg has a film thickness adjusted to be an optical path length in which a second cavity is generated. Further, in the sub-pixel 12B, the distance Lb between the anode 21 and the cathode 27 is an optical path length in which a third cavity is generated. That is, the hole injection layer 22, the hole transport layer 23, the organic light emitting layer 24, the electron transport layer 25, and the electron injection layer 26 have the distance Lb between the anode 21 and the cathode 27 in the subpixel 12B. The film thickness is adjusted to be the optical path length that causes Thereby, the light extraction efficiency can be improved. As a result, the element performance of the organic electroluminescent element 12-2 can be improved. At this time, the electron transport layer 25 can have a common film thickness in the subpixel 12R, the subpixel 12G, and the subpixel 12B. As a result, in the subpixel 12R, the subpixel 12G, and the subpixel 12B, the electron transport layer 25 can be configured by a common layer.

  In the present embodiment, the electron transport layer 25 can be composed of a common layer in the subpixel 12R, the subpixel 12G, and the subpixel 12B. Thereby, the electron transport layer 24 can be formed by batch film formation without using a mask. As a result, the electron transport layer 24 can be a common deposited film or sputtered film in the subpixel 12R, the subpixel 12G, and the subpixel 12B.

  In the present embodiment, the emission center 24a is disposed on the hole transport layer 23 side in the organic emission layer 24 in the subpixel 12R and the subpixel 12G, and the emission center 24a is provided in the organic emission layer 24 in the subpixel 12B. It is arrange | positioned at the inner side electron transport layer 25 side. Thereby, for example, as shown in FIG. 8, in each sub-pixel 12, the film thickness of the organic light emitting layer 24 can be set to a film thickness (45 nm to 80 nm) suitable for coating, and further, the hole transport layer. The total film thickness of 23 and the hole injection layer 22 can also be a film thickness (50 nm to 130 nm) suitable for coating. As a result, the organic electroluminescent element 12-2 in each sub-pixel 12 can be a coating-type element, so that the organic electroluminescent panel 10 can be enlarged at a low cost.

  By the way, it is desired to maximize light extraction with a coating type device that is easy to manufacture a large-sized panel at low cost. The coating type device refers to, for example, the organic light emitting element 12-2 in which the hole transport layer 23 and the organic light emitting layer 24 are formed by coating, and the electron transport layer 25 is collectively formed for the RGB pixels. Since the coating type device does not require a mask pattern technique, a large and inexpensive panel can be manufactured.

  However, in the coating type device, the electron transport layer 25 is formed in a lump. Therefore, the film thickness of the electron transport layer 25 is designed to be optimized for the blue pixel 12B having the lowest light emission efficiency and the maximum rate limiting of power. However, in such a case, there is a problem that light extraction at the red pixel 12R and the green pixel 12G is reduced.

  On the other hand, in the present embodiment, the thickness of the organic light emitting layer 24 is measured from the interface that is the place where the influence of quenching by the hole transport layer 23 made of a material having an absorption coefficient k of 0.1 or more and 0.6 or less is the largest. The light emission center 12a is a position retreated by a thickness greater than 0 and 0.4 or less when the thickness is 1. Thereby, while avoiding the influence of quenching by the hole transport layer 23, it is possible to suppress a decrease in strength due to the deviation from the resonance point. As a result, the element performance (light extraction efficiency) of the organic electroluminescent element can be improved.

  Further, in the present embodiment, the thickness of the organic light emitting layer 24 from the interface that is the place where the influence of quenching is the greatest due to the hole transport layer 23 made of a material having an absorption coefficient k of 0.1 or more and 0.6 or less. The light emission center 12a is a position retreated by a thickness of 0.1 to 0.2 when the thickness is 1. Thereby, while avoiding the influence of quenching by the hole transport layer 23, it is possible to further suppress the decrease in strength due to the deviation from the resonance point. As a result, the element performance (light extraction efficiency) of the organic electroluminescent element can be further improved.

<2. Application example>
[Application example 1]
Below, the application example of the organic electroluminescent apparatus 1 demonstrated in the said embodiment is demonstrated. The organic electroluminescent device 1 is a television signal, a digital camera, a notebook personal computer, a sheet-like personal computer, a portable terminal device such as a mobile phone, or a video camera. The present invention can be applied to display devices for electronic devices in various fields that display signals as images or videos.

  FIG. 17 is a perspective view of the appearance of the electronic apparatus 2 according to this application example. The electronic device 3 is, for example, a sheet-like personal computer having a display surface 320 on the main surface of the housing 310. The electronic device 2 includes the organic electroluminescent device 1 on the display surface 320 of the electronic device 2. The organic electroluminescent device 1 is arranged so that the organic electric field display panel 10 faces outward. In this application example, since the organic electroluminescent device 1 is provided on the display surface 320, the electronic device 2 with high luminous efficiency can be realized.

[Application example 2]
Below, the application example of the organic electroluminescent element 12-2 demonstrated in the said embodiment is demonstrated. The organic electroluminescent element 12-2 can be applied to a light source of a lighting device in various fields such as a desk or floor lighting device or a room lighting device.

  FIG. 18 shows the appearance of an indoor lighting device to which the organic electroluminescent element 12-2 is applied. This illuminating device has the illumination part 410 comprised including the 1 or several organic electroluminescent element 12-2, for example. The illumination units 410 are arranged on the ceiling 420 of the building at an appropriate number and interval. Note that the illumination unit 410 can be installed in an arbitrary place such as a wall 430 or a floor (not shown), not limited to the ceiling 420, depending on the application.

  In these illumination devices, illumination is performed by light from the organic electroluminescent element 12-2. Thereby, an illuminating device with high luminous efficiency can be realized.

  Although the present disclosure has been described with the embodiment, the present disclosure is not limited to the embodiment, and various modifications are possible. For example, in the above embodiment, the plurality of line banks 13 and the plurality of banks 15 are provided on the substrate 14, but instead of them, one pixel bank may be provided for each sub-pixel 12. Good.

  Further, for example, in the above embodiment, the microcavity structure of the red pixel 12R and the green pixel 12G has an optical path length at which a second cavity is generated. Furthermore, the microcavity structure of the blue pixel 12B has an optical path length in which a third cavity is generated. However, in the above-described embodiment, the microcavity structures of the red pixel 12R, the green pixel 12G, and the blue pixel 12B may be a combination different from the above. For example, in the above-described embodiment, the microcavity structure of the red pixel 12R, the green pixel 12G, and the blue pixel 12B may have an optical path length in which a first cavity or a second cavity is generated.

  In addition, the effect described in this specification is an illustration to the last. The effects of the present disclosure are not limited to the effects described in this specification. The present disclosure may have effects other than those described in this specification.

For example, this indication can take the following composition.
(1)
An organic electroluminescent device comprising an anode, an organic layer including a light emitting layer, and a cathode in this order,
In the organic layer, the first organic layer between the light emitting layer and the anode includes a hole transport layer made of a material having an absorption coefficient of 0.01 or more and 0.06 or less,
The light emitting layer has a light emission center at a position retreated from the anode side interface of the light emitting layer by a thickness larger than 0 and less than 0.35 when the thickness of the light emitting layer is 1. And
The organic electroluminescent device has a microcavity structure in which the position of the interface is a resonance point.
(2)
The light emitting layer is located at a position that is receded from the interface on the anode side of the light emitting layer by a thickness of 0.1 to 0.2 when the thickness of the light emitting layer is 1. The organic electroluminescence device according to (1), having a center.
(3)
The first distance between the interface and the anode and the second distance between the interface and the cathode are such that the light emitted from the emission center resonates by the microcavity structure. The organic electroluminescent device according to (1) or (2).
(4)
In the organic layer, the second organic layer between the light emitting layer and the cathode is a deposited film or a sputtered film,
The organic light emitting element according to any one of (1) to (3), wherein the light emitting layer and the first organic layer are coating films.
(5)
The organic electroluminescence device according to any one of (1) to (4), wherein the hole transport layer is an insolubilized hole transport layer.
(6)
With red, green and blue pixels,
Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescence device including an anode, an organic layer including a light emitting layer, and a cathode in this order.
A material having an absorption coefficient of 0.01 or more and 0.06 or less in the first organic layer between the light emitting layer and the anode in the organic layer of at least one of the red pixel and the green pixel A hole transport layer composed of
The light emitting layer in the pixel having the hole transport layer has a thickness of more than 0 and less than 0.35 when the thickness of the light emitting layer is 1 from the interface of the light emitting layer on the hole transport layer side. Having a first emission center at a position retracted by that amount,
The organic electroluminescent panel of the pixel having the hole transport layer has a microcavity structure in which the position of the interface serves as a resonance point.
(7)
In the organic layer, the second organic layer between the light emitting layer and the cathode includes an electron transport layer,
The electron transport layer is a deposited film or a sputtered film,
The organic light emitting panel according to (6), wherein the light emitting layer and the first organic layer are coating films.
(8)
In the red pixel, the green pixel, and the blue pixel, the electron transport layer is configured by a common layer. The organic electroluminescent panel according to (7).
(9)
The organic light emitting panel according to (7) or (8), wherein in the blue pixel, the light emitting layer has a second light emission center at a position on the electron transport layer side of the light emitting layer.
(10)
An organic electroluminescent panel;
A drive circuit for driving the organic electroluminescent panel,
The organic electroluminescent panel has a red pixel, a green pixel and a blue pixel,
Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescence device including an anode, an organic layer including a light emitting layer, and a cathode in this order.
In the organic layer of at least one of the red pixel, the green pixel, and the blue pixel, the first organic layer between the light emitting layer and the anode has an absorption coefficient of 0.01 or more and 0.0. Including a hole transport layer composed of a material of 06 or less,
The light emitting layer in the pixel having the hole transport layer has a thickness of more than 0 and less than 0.35 when the thickness of the light emitting layer is 1 from the interface of the light emitting layer on the hole transport layer side. It has a light emission center at a position retreated by that amount,
The organic electroluminescent device in the pixel having the hole transport layer has a microcavity structure in which the position of the interface serves as a resonance point.
(11)
With an organic electroluminescent device,
The organic electroluminescent device is:
An organic electroluminescent panel;
A driving circuit for driving the organic electroluminescent panel;
The organic electroluminescent panel has a red pixel, a green pixel and a blue pixel,
Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescence device including an anode, an organic layer including a light emitting layer, and a cathode in this order.
In the organic layer of at least one of the red pixel, the green pixel, and the blue pixel, the first organic layer between the light emitting layer and the anode has an absorption coefficient of 0.01 or more and 0.0. Including a hole transport layer composed of a material of 06 or less,
The light emitting layer in the pixel having the hole transport layer has a thickness of more than 0 and less than 0.35 when the thickness of the light emitting layer is 1 from the interface of the light emitting layer on the hole transport layer side. It has a light emission center at a position retreated by that amount,
The organic electroluminescent device in a pixel having the hole transport layer has an electronic device having a microcavity structure in which the position of the interface is a resonance point.

  DESCRIPTION OF SYMBOLS 1 ... Organic electroluminescent apparatus, 10 ... Organic electroluminescent panel, 11 ... Pixel, 12, 12R, 12G, 12B ... Subpixel, 12-1 ... Pixel circuit, 12-2, 12r, 12g, 12b ... Organic electroluminescent element , 13 ... line bank, 14 ... substrate, 15 ... bank, 16 ... groove, 20 ... controller, 21 ... anode, 22 ... hole injection layer, 23 ... hole transport layer, 24, 24a ... light emitting region, 25 ... electron Transport layer 26 ... Electron injection layer 27 ... Cathode 28 ... Sealing layer 30 ... Driver 31 ... Horizontal selector 32 ... Light scanner Tr1 ... Drive transistor Tr2 ... Select transistor Cs ... Retention capacitor DSL ... Power line, DTL ... signal line, Vgs ... gate-source voltage, Vsig ... signal voltage, WSL ... selection line.

Claims (11)

An organic electroluminescent device comprising an anode, an organic layer including a light emitting layer, and a cathode in this order,
In the organic layer, the first organic layer between the light emitting layer and the anode includes a hole transport layer made of a material having an absorption coefficient of 0.01 or more and 0.06 or less,
The light emitting layer has a light emission center at a position retreated from the anode-side interface of the light emitting layer by a thickness greater than 0 and 0.4 or less when the thickness of the light emitting layer is 1. And
The organic electroluminescent device has a microcavity structure in which the position of the interface is a resonance point. The light emitting layer is located at a position that is receded from the interface on the anode side of the light emitting layer by a thickness of 0.1 to 0.2 when the thickness of the light emitting layer is 1. The organic electroluminescent element according to claim 1, which has a center. The first distance between the interface and the anode and the second distance between the interface and the cathode are such that the light emitted from the emission center resonates by the microcavity structure. The organic electroluminescent element according to claim 1 or 2. In the organic layer, the second organic layer between the light emitting layer and the cathode is a deposited film or a sputtered film,
The organic electroluminescent element according to any one of claims 1 to 3, wherein the light emitting layer and the first organic layer are coating films. The organic electroluminescent element according to any one of claims 1 to 4, wherein the hole transport layer is an insolubilized hole transport layer. With red, green and blue pixels,
Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescence device including an anode, an organic layer including a light emitting layer, and a cathode in this order.
A material having an absorption coefficient of 0.01 or more and 0.06 or less in the first organic layer between the light emitting layer and the anode in the organic layer of at least one of the red pixel and the green pixel A hole transport layer composed of
The light emitting layer in the pixel having the hole transport layer has a thickness of greater than 0 and less than or equal to 0.4 from the interface of the light emitting layer on the hole transport layer side when the thickness of the light emitting layer is 1. Having a first emission center at a position retracted by that amount,
The organic electroluminescent panel of the pixel having the hole transport layer has a microcavity structure in which the position of the interface serves as a resonance point. In the organic layer, the second organic layer between the light emitting layer and the cathode includes an electron transport layer,
The electron transport layer is a deposited film or a sputtered film,
The organic electroluminescent panel according to claim 6, wherein the light emitting layer and the first organic layer are coating films. The organic electroluminescent panel according to claim 7, wherein the electron transport layer is formed of a common layer in the red pixel, the green pixel, and the blue pixel. 9. The organic electroluminescent panel according to claim 7, wherein, in the blue pixel, the light emitting layer has a second light emission center at a position on the electron transport layer side of the light emitting layer. An organic electroluminescent panel;
A drive circuit for driving the organic electroluminescent panel,
The organic electroluminescent panel has a red pixel, a green pixel and a blue pixel,
Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescence device including an anode, an organic layer including a light emitting layer, and a cathode in this order.
In the organic layer of at least one of the red pixel, the green pixel, and the blue pixel, the first organic layer between the light emitting layer and the anode has an absorption coefficient of 0.01 or more and 0.0. Including a hole transport layer composed of a material of 06 or less,
The light emitting layer in the pixel having the hole transport layer has a thickness of greater than 0 and less than or equal to 0.4 from the interface of the light emitting layer on the hole transport layer side when the thickness of the light emitting layer is 1. It has a light emission center at a position retreated by that amount,
The organic electroluminescent device in the pixel having the hole transport layer has a microcavity structure in which the position of the interface serves as a resonance point. With an organic electroluminescent device,
The organic electroluminescent device is:
An organic electroluminescent panel;
A driving circuit for driving the organic electroluminescent panel;
The organic electroluminescent panel has a red pixel, a green pixel and a blue pixel,
Each of the red pixel, the green pixel, and the blue pixel has an organic electroluminescence device including an anode, an organic layer including a light emitting layer, and a cathode in this order.
In the organic layer of at least one of the red pixel, the green pixel, and the blue pixel, the first organic layer between the light emitting layer and the anode has an absorption coefficient of 0.01 or more and 0.0. Including a hole transport layer composed of a material of 06 or less,
The light emitting layer in the pixel having the hole transport layer has a thickness of greater than 0 and less than or equal to 0.4 when the thickness of the light emitting layer is 1 from the interface of the light emitting layer on the hole transport layer side. It has a light emission center at a position retreated by that amount,
The organic electroluminescent device in a pixel having the hole transport layer has an electronic device having a microcavity structure in which the position of the interface is a resonance point.

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