TWI425865B - Method for manufacturing organic light emitting diode device - Google Patents

Description

Method for manufacturing organic light emitting diode device

The present invention relates to a method for fabricating an organic light-emitting diode device, and more particularly to a method for fabricating an organic light-emitting diode device in which an organic material layer is treated by heating.

Organic Electro-luminescence Display (Organic EL Display) is also known as Organic Light Emitting Diode (OLED) in 1987 by Kodak's CW Tang and SA VanSlyk et al. Firstly, it is made by vacuum evaporation, and the hole transport material and the electron transport material are respectively plated on transparent indium tin oxide (ITO) glass, and then a metal electrode is vapor-deposited to form The self-luminous organic light-emitting diode device is new because of its high brightness, fast screen response, short and light color, full color, no viewing angle difference, no need for liquid crystal display backlight, saving light source and power consumption. A generation of displays.

Please refer to the cross-sectional view of a conventional organic light-emitting diode device as shown in the first figure. The structure of the conventional organic light-emitting diode device A includes a transparent substrate A1 and a transparent anode from bottom to top. A2 (Indium Tin Oxide, ITO), Hole Transporting Layer A3 (HTL), an Organic Emitting Layer (EL), an Electron Transport Layer (ETL), an electron Injection layer A6 (Electron Injection Layer, EIL) and a metal cathode A7. When a forward bias voltage is applied, the hole is injected from the anode A2, and the electron is injected from the cathode A7. The potential difference caused by the applied electric field causes the electrons and holes to move in the film, and further in the organic light-emitting layer A4. Produce a recombination. Part of the energy released by the electron hole combination excites the luminescent molecules of the organic luminescent layer A4 to become an excited state. When the luminescent molecules decay from the excited state to the ground state, a certain proportion of the energy is released in the form of photons, and the emitted Light is organic electroluminescence.

Although organic light-emitting diodes have many excellent properties and advantages, in order to improve the luminous efficacy of organic light-emitting diodes, many research units and researchers are working on the improvement of organic light-emitting diodes in order to reduce them. Cost and increase the luminous efficacy. At present, most of the research on organic light-emitting diodes focuses on the improvement of structure, but the way of transforming the structure is very limited for the cost-saving issue.

In view of this, it is necessary to provide an improved manufacturing method from the manufacturing method of the organic light emitting diode, which can simultaneously achieve cost saving and increase the luminous efficacy of the organic light emitting diode.

Therefore, in view of the aforementioned problems and deficiencies, the inventors have accumulated experience over many years, and exerted imagination and creativity. After continuous trial and modification, a method of manufacturing an organic light-emitting diode device of the present invention has been invented.

The main object of the present invention is to provide a method for fabricating an organic light-emitting diode device, which improves the overall light-emitting efficiency by improving the material processing, and the invention can be increased with less manufacturing cost compared to the complicated structural design improvement. The effect of luminous efficiency.

Another object of the present invention is to provide an organic light emitting diode device which can achieve an effect of increasing luminous efficiency at a lower manufacturing cost by a simple structural design and improved material processing.

In order to achieve the above object, the present invention discloses a method for fabricating an organic light emitting diode device, characterized in that at least one organic material layer comprises the following manufacturing steps: (1) providing a material required for at least one organic material layer, and formulating the same a solution state; (2) heating the organic material solution to a first specific temperature range; (3) forming an organic material solution that has been heated to the first specific temperature range into a film; and (4) the organic material The layer is baked at a second specific temperature range.

In order to achieve the above-mentioned purpose and effect, the inventors have obtained a method for manufacturing an organic light-emitting diode device of the present invention by simple structural design and improvement in material processing, under constant correction and adjustment.

First, the core technical features of a method for fabricating an organic light-emitting diode device according to the present invention are described. Referring to FIG. 2, a step-by-step diagram of a method for manufacturing an organic material layer of the present invention includes the following steps. Providing a material required for an organic material layer, which is formulated into a solution state (step 001); heating the organic material solution to a first specific temperature range (step 002), wherein the first specific temperature range is 25 ° C to 300 ° C; the organic material solution heated to the first specific temperature range is subjected to a film forming action (step 003), wherein the film forming method comprises inkjet printing, screen printing, spin coating, and Contact transfer; and baking the organic material layer at a second specific temperature range (step 004), wherein the second specific temperature range is 25 ° C to 300 ° C.

In the above method for fabricating an organic material layer, the organic material layer may contain only one light-emitting layer and be heated in step 002. Alternatively, the organic material layer may include both an auxiliary light-emitting layer and a light-emitting layer, and the two may be heated separately or simultaneously. Furthermore, the organic material layer may include a first auxiliary light-emitting layer, a light-emitting layer and a second auxiliary light-emitting layer, and the three may be heated separately or simultaneously. In addition to the combination of the above organic material layers, the number of the light-emitting layer and the auxiliary light-emitting layer can be increased to adjust the light-emitting efficiency of the organic light-emitting diode.

Next, the organic material layer including a first auxiliary light-emitting layer, a light-emitting layer and a second auxiliary light-emitting layer is used as a preferred embodiment of the present invention, and the organic matter of the present invention is hereinafter described by the preferred embodiment. The complete structure of the light-emitting diode device and its manufacturing method are described in detail, and the luminous efficiency of different heating temperatures is compared.

First, please refer to the third to seventh figures, the third figure is a schematic structural diagram of the organic light emitting diode device of the preferred embodiment of the present invention, and the fourth figure is a schematic diagram of the molecular structure of a PEDOT:PSS. Figure 5 is a schematic diagram of the molecular structure of a CBP, the sixth diagram is a schematic diagram of the molecular structure of a FIrpic, and the seventh diagram is a schematic diagram of the molecular structure of a TPBi.

The organic light-emitting diode device 1 comprises at least one substrate 10, which is composed of a transparent substrate, which is a glass substrate. In practical applications, a polymer substrate can be further used; The first conductive layer 12 is disposed on the substrate 10; a first auxiliary light-emitting layer 12 is disposed on the first conductive layer 11, the first auxiliary light-emitting layer 12 further includes a carrier injection layer, and a carrier layer The sub-transport layer, a carrier blocking layer and an exciton-restricted layer (not shown). In the present invention, the material of the first auxiliary luminescent layer 12 is PEDOT:PSS(Poly(3,4-ethylenedioxythiophene) poly (styrenesulfonate)) (see FIG. 3 for molecular structure); a light-emitting layer 13 is disposed on the first auxiliary light-emitting layer. In the present invention, the main system of the light-emitting layer 13 is a phosphorescent material CBP (molecular structure) See the fourth figure), and the doped material is a blue phosphorescent material FIrpic (iridium(III) bis(4,6-di-fluolophenyl)-pyridinato-N, C2) picolinate) (see Figure 5 for molecular structure) ), however, in practical applications, the doped material can also be used in any other type of phosphorescence A material or any type of phosphorescent material, more preferably a phosphorescent material of any kind and a mixture of phosphorescent materials of any kind; a second auxiliary light-emitting layer 14 is disposed on the light-emitting layer 13, The second auxiliary light-emitting layer 14 further includes a carrier injection layer, a carrier transport layer, a carrier barrier layer and an exciton-limited layer (not shown). In the present invention, the second auxiliary light-emitting layer 14 The material is TPBi (1,3,5-tris(Nphenylbenzimidazol-2-yl)-benzene) (see FIG. 6 for molecular structure); and a second conductive layer 15 is disposed on the second auxiliary light-emitting layer 14 on.

Referring to FIG. 8 , FIG. 8 is a schematic diagram showing a manufacturing method of an organic light emitting diode device according to a preferred embodiment of the present invention. The manufacturing method includes the following steps: providing a substrate (step 101); providing a first a conductive layer disposed on the substrate (step 102); providing a first auxiliary light-emitting layer, a light-emitting layer, and a second auxiliary light-emitting layer, and preparing the solution into a solution state by using a toluene solvent (Step 103): heating the luminescent layer material solution to a first specific temperature range (Step 104), wherein the first specific temperature range is 25 ° C to 300 ° C; the first auxiliary luminescent layer material solution, The luminescent layer material solution heated to the first specific temperature range and the second auxiliary luminescent layer material solution are sequentially formed on the first conductive layer by spin coating (step 105), and in actual application, by spraying Performing film formation by ink printing, screen printing or contact transfer; baking the first auxiliary light-emitting layer, the light-emitting layer and the second auxiliary light-emitting layer at a second specific temperature range (step 106), the second specific temperature range 25 deg.] C to 300 deg.] C; and providing a second conductive layer, and which is disposed on the second auxiliary light emitting layer (step 107).

In addition to the above-described method of heating the light-emitting layer material solution in advance, the first auxiliary light-emitting layer material solution or the second auxiliary light-emitting layer material solution may be separately heated in advance, and two or more layers may be selectively heated at the same time.

In order to confirm that the preheating of the luminescent layer material solution in the preferred embodiment of the present invention contributes to the improvement of the energy efficiency of the device, the luminescent layer material solution is preheated to 75 ° C, 50 ° C and 25 ° C to prepare an organic light emitting diode. Device and compare the energy efficiency of the components.

As shown in the following list 1, the heating temperature of the luminescent layer material solution affects the efficiency of the component containing the CBP host material. When the brightness of the element is 100 and 1000 cd/m ² , the energy of the luminescent layer material solution heated to 75 ° C is the highest, followed by It is 50 ° C, and finally 25 ° C; thus it can be proved that preheating the light-emitting layer material solution can increase the energy efficiency of the element, and the higher the heating temperature, the more significant the efficiency improvement.

In addition to the use of CBP as the host material of the light-emitting layer, PVK (poly(N-vinylcarbazole)) may be used as the host material of the light-emitting layer, and the molecular structure of PVK is referred to FIG. In order to know the influence of the heating temperature on the efficiency of the element containing the PVK main body, the luminescent layer solution was previously heated to 60 ° C and 30 ° C, respectively. As shown in Table 2, when the brightness of the element is 100 and 1000 cd/m ² , the energy efficiency of the material of the light-emitting layer material solution heated to 60 ° C is higher than that of heating to 30 ° C; thus, it can be proved that the light-emitting layer is previously performed. Heating increases the energy efficiency of the component, and the higher the heating temperature, the more significant the efficiency improvement.

The structure of the organic light-emitting diode of the present invention and its special manufacturing method can be clearly understood through the above detailed description of the preferred embodiments of the present invention, and the utility is proved by the test results. The structure of the present invention and its manufacturing method have the following advantages:

(1) The present invention can increase the luminous efficiency of the component by preheating the first auxiliary luminescent layer, the luminescent layer or the second auxiliary luminescent layer, and the invention can reduce the manufacturing cost and increase the luminous efficiency compared to the complicated component structure design. Effect.

(2) The present invention achieves an effect of increasing luminous efficiency by a simple structural design and a process process, which can achieve a lower manufacturing cost.

The embodiments described above are merely illustrative of the technical spirit and characteristics of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention. Equivalent variations or modifications in accordance with the spirit of the invention are still intended to be included within the scope of the invention.

The inventor has been continually conceived and modified to finally obtain the design of the present invention, and possesses the above-mentioned many advantages. It is an excellent invention, and should conform to the requirements of the invention patent, and the application is made, and the review committee can give the invention early. Patents to protect the rights of inventors.

A. . . Conventional organic light emitting diode device

A1. . . Transparent substrate

A2. . . Transparent anode

A3. . . Hole transport layer

A4. . . Organic light emitting layer

A5. . . Electronic transport layer

A6. . . Electron injection layer

A7. . . Metal cathode

1. . . Organic light emitting diode device

10. . . Substrate

11. . . First conductive layer

12. . . First auxiliary light emitting layer

13. . . Luminous layer

14. . . Second auxiliary light emitting layer

15. . . Second conductive layer

001~004. . . Manufacturing method step number of organic material layer

101~107. . . Step number of manufacturing method of organic light emitting diode device according to preferred embodiment of the present invention

The first figure is a cross-sectional view of a conventional organic light emitting diode device;

The second drawing is a step diagram of a method for manufacturing an organic material layer of the present invention;

3 is a schematic structural view of an organic light emitting diode device according to a preferred embodiment of the present invention;

The fourth figure is a schematic diagram of the molecular structure of EDOT:PSS;

The fifth figure is a schematic diagram of the molecular structure of a CBP;

The sixth figure is a schematic diagram of the molecular structure of FIrpic;

The seventh figure is a schematic diagram of the molecular structure of a TPBi;

8 is a diagram showing the steps of a method for manufacturing an organic light emitting diode device according to the preferred embodiment of the present invention; and

The ninth diagram is a schematic diagram of the molecular structure of PVK.

001~004. . . Machine material layer manufacturing method step number

Claims (4)

A method for fabricating an organic light-emitting diode device, characterized in that at least one organic material layer comprises the following manufacturing steps: (1) providing a material required for at least one organic material layer, and formulating it into a solution state; (2) The organic material solution is heated to 25 ° C to 75 ° C; (3) the organic material solution heated to 25 ° C to 75 ° C is formed into a film; and (4) the organic material layer is baked at a temperature of 25 ° C to 300 ° C . The method of manufacturing an organic light-emitting diode device according to the above aspect of the invention, wherein the organic material layer is at least one light-emitting layer, and in the step (2), the light-emitting layer is heated. The method for fabricating an organic light-emitting diode device according to claim 1, wherein the organic material layer comprises at least one auxiliary light-emitting layer and at least one light-emitting layer, and in the step (2), the method is selected. The heating is performed on the at least one auxiliary luminescent layer and the at least one luminescent layer. The method for manufacturing an organic light-emitting diode device according to the first aspect of the invention, wherein the film forming method described in the step (3) can be selected and used by the following methods: inkjet printing, screen printing, spin coating, and Contact transfer.