CN111697006A - Display panel and preparation method thereof - Google Patents

Abstract

The invention discloses a display panel and a preparation method of the display panel. The display panel includes: an active layer; Covering the active layer, the down-conversion layer converts blue or ultraviolet light directed toward the active layer into red light. Compared with the existing display panel, the present invention adds at least one down-conversion layer in the display panel to convert the blue light or ultraviolet light emitted to the active layer into red light, because the red light The energy level of the light is lower than the blue light and the ultraviolet light, and the red light has less influence on the stability of the active layer; at the same time, a mask process is saved, the production cost is reduced, and the transmittance and aperture ratio are improved .

Description

Display panel and method for producing the same

technical field

The present invention relates to the field of display technology, in particular to a display panel and a method for preparing the display panel.

Background technique

Thin Film Transistor (TFT) is the main driving element in current liquid crystal display devices and active matrix driven organic electroluminescence display devices, and is directly related to the development direction of high-performance flat panel display devices. Indium Gallium Zinc Oxide (IGZO) has become a research hotspot in the field of thin film transistor technology due to its high mobility, suitability for large-area production, and easy conversion from amorphous silicon (a-Si) processes. .

In the production process of organic light-emitting diodes (Organic Light-Emitting Diode, OLED), there are several ultraviolet (Ultraviolet, UV) irradiation processes, such as cleaning UV before evaporation to remove organic substances on the glass surface, packaging UV curing and so on. However, the IGZO active layer in IGZO-TFT is very sensitive to the process and environment, because the UV photon energy is higher than the band gap of the oxide semiconductor and electron-hole pairs are generated, which reduces the threshold voltage, which will be detrimental to its stability. influences.

The current device structure often uses an Etch-Stop Layer (ESL) and adds a metal shading layer to protect the IGZO active layer, which is not conducive to reducing the cost of the TFT process. ) and the etch barrier layer, so that the channel size of the TFT device is larger and the parasitic capacitance is larger. However, the etching barrier layer and the metal light shielding layer cannot completely prevent UV light from irradiating IGZO, and for transparent devices, the structure of the etching barrier layer and the metal light shielding layer reduces the transmittance of the device.

To sum up, the current display panels have technical problems such as high production cost, poor stability of the active layer, and low panel transmittance and aperture ratio.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a display panel and a manufacturing method of the display panel, which are used to solve the technical problems of high production cost, poor stability of the active layer, and low panel transmittance and aperture ratio of the current display panel.

In order to solve the above problems, in the first aspect, the present invention provides a display panel, including:

active layer;

A down-conversion layer, disposed on at least one side of the active layer, the orthographic projection of the down-conversion layer covers the active layer, and the down-conversion layer converts the blue light or ultraviolet light emitted to the active layer into red light.

In some embodiments of the present invention, it further includes a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a flat layer, and a pixel definition layer that are stacked in sequence, and the active layer is disposed on the buffer layer , the down-conversion layer is disposed between the base substrate and the buffer layer.

In some embodiments of the present invention, when the display panel includes two of the down-conversion layers, another of the down-conversion layers is disposed between the passivation layer and the planarization layer.

In some embodiments of the present invention, it further includes a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a flat layer and a pixel definition layer that are stacked in sequence, and the down-conversion layer is arranged on the pixel definition layer on the side surface away from the flat layer.

In some embodiments of the present invention, the thickness of the down-conversion layer is less than or equal to 1 μm.

In a second aspect, the present invention provides a method for manufacturing a display panel, the method for manufacturing the display panel according to any one of the first aspects, comprising the steps of: providing an active layer; and

A down-conversion layer is prepared, and the down-conversion layer is formed on at least one side of the active layer by spin coating or printing, and the down-conversion layer converts blue light or ultraviolet light emitted to the active layer into red light.

In some embodiments of the present invention, preparing the down-conversion layer includes: firstly dispersing the down-conversion luminescent material uniformly in the transparent polymer material, then dissolving in ethanol, and then performing spin coating or printing treatment, wherein the down-conversion luminescent material is The doping concentration of the conversion layer is 1.5×10-5～2%, and the light absorption range is 260nm～420nm.

In some embodiments of the present invention, the down-conversion luminescent material is europium-doped yttrium vanadate or a rare earth complex, and the transparent polymer material is ethylene-vinyl acetate copolymer or polyvinyl alcohol.

In some embodiments of the present invention, it further includes a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a flat layer and a pixel definition layer formed in sequence, and the active layer is formed on the buffer layer, The down-conversion layer is formed between the base substrate and the buffer layer, and/or between the passivation layer and the planarization layer.

In some embodiments of the present invention, it further includes a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a planarization layer and a pixel definition layer formed in sequence, and the down-conversion layer is formed away from the pixel definition layer. on one side surface of the flat layer.

Compared with the existing display panel, the present invention adds at least one down-conversion layer in the display panel to convert the blue light or ultraviolet light emitted to the active layer into red light, because the red light The energy level of the light is lower than the blue light and the ultraviolet light, and the red light has less influence on the stability of the active layer; at the same time, a mask process is saved, the production cost is reduced, and the transmittance and aperture ratio are improved .

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic structural diagram of a display panel in an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a display panel in another embodiment of the present invention;

3 is a schematic structural diagram of a display panel in yet another embodiment of the present invention; and

FIG. 4 is a flow chart of a preparation method in an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., or The positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

The current display panel has technical problems of high production cost, poor stability of the active layer, and low panel transmittance and aperture ratio.

Based on this, embodiments of the present invention provide a display panel and a method for fabricating the display panel, which will be described in detail below.

First, an embodiment of the present invention provides a display panel, as shown in FIG. 1 , which is a schematic structural diagram of a display panel in an embodiment of the present invention. The display panel includes an active layer 101; and a down-conversion layer 102 disposed on at least one side of the active layer 101. The orthographic projection of the down-conversion layer 102 covers the active layer 101. Layer 102 converts blue or ultraviolet light directed towards the active layer 101 into red light.

Compared with the existing display panel, the present invention adds at least one down-conversion layer 102 in the display panel to convert the blue light or ultraviolet light (shaded arrows in the figure, shading arrows in the figure) to the active layer 101. The same below) is converted into red light (the hollow arrow in the figure, the same below), since the energy level of the red light is lower than the blue light and the ultraviolet light, the red light has less influence on the stability of the active layer 101 ; At the same time, a mask process is saved, the production cost is reduced, and the transmittance and aperture ratio are improved.

In the embodiment of the present invention, the display panel further includes a base substrate 103, a buffer layer 104, an interlayer dielectric layer 105, a passivation layer 106, a flat layer 107 and a pixel definition layer 108, which are stacked in sequence. The layer 101 is disposed on the buffer layer 104 , and the down-conversion layer 102 is disposed between the base substrate 103 and the buffer layer 104 .

When the display panel is a thin film transistor with a top-gate structure, the display panel further includes a gate insulating layer 109, a gate metal layer 110, a source-drain metal layer 111, a color filter layer 112, a conductive thin film layer (Indium Tin Oxide (ITO) 113 , a light-emitting layer 114 and a cathode 115 , wherein the active layer 101 is on the buffer layer 104 , and the gate insulating layer 109 is on the active layer 101 . The light is emitted toward the active layer 101 from the side of the base substrate 103. In some embodiments, in order to protect the active layer 101, a metal light shielding layer is provided during the incident process, but the metal The light-shielding layer is easily affected by the floating gate effect, and the voltage on the band varies, resulting in unstable voltage in the working state of the TFT. In the embodiment of the present invention, the down-conversion layer 102 is used to replace the metal light shielding layer during the incident process. Specifically, the down-conversion layer 102 is disposed between the base substrate 103 and the buffer layer 104 During this time, the light from the bottom in the figure passes through the base substrate 103 and then reaches the down-conversion layer 102 .

On the basis of the above embodiment, as shown in FIG. 2 , FIG. 2 is a schematic structural diagram of a display panel in another embodiment of the present invention. When the display panel includes two down-conversion layers 102, which are named as the first down-conversion layer 102 and the second down-conversion layer 116 in this embodiment, they are disposed on the base substrate 103 and the buffer layer. The position of the first down-conversion layer 102 between 104 remains unchanged, and another second down-conversion layer 116 is disposed between the passivation layer 106 and the flat layer 107 . The second down-conversion layer 116 can not only convert at least part of the blue light or ultraviolet light emitted from the pixel definition layer 108 to the active layer 101 into red light, but also can convert the light emitted from the light-emitting layer 114 to the active layer 101 . At least part of the blue light or ultraviolet light emitted by the active layer 101 is converted into red light. At the same time, because the energy level of the red light is relatively low, after absorbing the blue light or ultraviolet light of high-energy photons, the down-conversion layer 116 emits more light. A number of low-energy photons, that is, emitting red light with greater brightness, after being reflected by the metal electrode, increase the brightness of the light-emitting side.

In another embodiment of the present invention, as shown in FIG. 3 , FIG. 3 is a schematic structural diagram of a display panel in another embodiment of the present invention. The display panel includes an active layer 201, a down conversion layer 202, a base substrate 203, a buffer layer 204, an interlayer dielectric layer 205, a passivation layer 206, a flat layer 207, and a pixel definition layer 208, which are stacked in sequence. The down-conversion layer 202 is disposed on a side surface of the pixel definition layer 208 away from the flat layer 207 .

When the display panel is an etch barrier type thin film transistor, the display panel further includes a gate insulating layer 209, an etch barrier layer 210, a source/drain metal layer 211, a color filter layer 212, a conductive thin film layer 213, and a light emitting layer 214 and a cathode 215, wherein the gate insulating layer 209 is on the buffer layer 204, the active layer 201 is on the gate insulating layer 209, and the etch stop layer 210 is on the active layer 201 on. The light is emitted from the pixel definition layer 208 to the active layer 201, and the down-conversion layer 202 is disposed during the incident process. Specifically, the down-conversion layer 202 is disposed in the pixel definition layer. On the side surface of 208 away from the flat layer 207, the light from the upper part of the figure is directly incident on the down-conversion layer 202, and at least part of the blue light or ultraviolet light in the light is converted into red light, red light Continue to emit light according to the original propagation path, since the energy level of red light is low, the influence on the active layer 101 is small.

Preferably, the thickness of the down-conversion layer 102 is less than or equal to 1 μm. It can be understood that, if the second down-conversion layer 116 exists, the thickness of the second down-conversion layer 116 is also less than or equal to 1 μm, and the active The material of the layer 101 is metal oxide semiconductor, and more preferably, the material of the active layer 101 is indium gallium zinc oxide.

In order to better manufacture the display panel in the embodiment of the present invention, on the basis of the display panel, the embodiment of the present invention also provides a preparation method of the display panel, and the preparation method is used to prepare the above-mentioned embodiment. display panel described in .

The preparation method includes the following steps: providing an active layer 101; and

Prepare a down conversion layer, and form the down conversion layer 102 on at least one side of the active layer 101 by spin coating or printing, and the down conversion layer converts the blue light or ultraviolet light emitted to the active layer into red Light.

Specifically, preparing the down-conversion layer 102 includes: firstly dispersing the down-conversion luminescent material uniformly in the transparent polymer material, then dissolving in ethanol, and then performing spin coating or printing processing.

Preferably, the doping concentration of the down-conversion layer 102 is 1.5×10 −5˜2%, and the light absorption range is 260 nm˜420 nm. It can be understood that the main wavelength of blue light is 400nm-450nm, the main wavelength of ultraviolet light is 10nm-400nm, and the absorption range of the down conversion layer 102 includes at least part of blue light or ultraviolet light.

Preferably, the down-conversion light-emitting material is yttrium-doped europium vanadate (YVO4:Eu3+) or a rare earth complex (Eu(DBM)3Phen); the transparent polymer material is ethylene-vinyl acetate copolymer (EVA) or polyethylene Vinyl alcohol (PVA).

In an embodiment of the present invention, as shown in FIG. 4 , FIG. 4 is a flow chart of a preparation method in an embodiment of the present invention. The preparation method of the display panel includes the following steps:

S1. Dissolving PVA doped with 1.5×10-5～2% Eu(DBM)3Phen in ethanol, spin coating on the base substrate 103 to form the down conversion layer 102;

S2, preparing a buffer layer 104 on the down-conversion layer 102;

S3, depositing an active layer 101, a gate insulating layer 109 and a gate metal layer 110 in sequence on the buffer layer 104;

S4, depositing an interlayer dielectric layer 105 on the gate metal layer 110;

S5, depositing a source-drain metal layer 111 on the interlayer dielectric layer 105, and depositing a passivation layer 106 on the source-drain metal layer 111;

S6 , the color filter layer 112 , the flat layer 107 , the conductive thin film layer 113 , the pixel definition layer 108 , the light-emitting layer 114 and the cathode 115 are sequentially prepared on the passivation layer 106 .

S7, performing encapsulation processing.

Specifically, step S3 further includes: performing dry etching processing on the gate insulating layer 109 and wet etching processing on the gate metal layer 110 , wherein the active layer 101 and the gate metal layer are prepared. The layer 110 is deposited by physical vapor deposition, and the gate insulating layer 109 is prepared by chemical vapor deposition, and the material of the gate insulating layer 109 is silicon nitride.

Step S5 also includes performing wet etching on the source-drain metal layer 111 , the passivation layer 106 is made of silicon nitride, and the passivation layer 106 protects the source-drain metal layer 111 .

In step S6, the light-emitting layer 114 is prepared by an evaporation method, and the cathode 115 is prepared by an evaporation method or a magnetron sputtering method.

In this embodiment, the metal light shielding layer is replaced by the down-conversion layer 102, which saves a mask process and reduces the production cost.

On the basis of the above-mentioned embodiment, in another embodiment, S5 further includes: dissolving PVA doped with 1.5×10-5～2% Eu(DBM)3Phen in ethanol, on the passivation layer 106 Printing the second down-conversion layer 116, wherein the second down-conversion layer 116 is formed between the passivation layer 106 and the planarization layer 107, and the orthographic projection of the second down-conversion layer 116 can cover the active layer 101 .

In another embodiment of the present invention, the preparation method is similar to the above-mentioned preparation method, except that in step S3: the gate insulating layer 209, the active layer 201 and the etching are sequentially deposited on the buffer layer 204 The barrier layer 210; and the lower conversion layer 202 is not spin-coated on the base substrate 203, but in step S7, the PVA doped with 1.5×10-5～2%Eu(DBM)3Phen is dissolved The down-conversion layer 202 is formed by spin coating on the surface of the pixel definition layer 208 away from the flat layer 207 in ethanol, and then encapsulation processing is performed.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to the above detailed description of other embodiments, and details are not repeated here. During specific implementation, the above units or structures can be implemented as independent entities, or can be arbitrarily combined to be implemented as the same or several entities. The specific implementation of the above units, structures or operations can refer to the previous method embodiments. It is not repeated here.

The embodiments of the present invention have been introduced in detail above, and specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; at the same time, for Those skilled in the art, according to the idea of the present invention, will have changes in the specific embodiments and application scope. To sum up, the content of this specification should not be construed as a limitation of the present invention.

Claims (10)

1. A display panel, wherein the display panel comprises: the active layer; and A down-conversion layer, disposed on at least one side of the active layer, the orthographic projection of the down-conversion layer covers the active layer, and the down-conversion layer converts the blue light or ultraviolet light emitted to the active layer into red light. 2 . The display panel according to claim 1 , further comprising a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a flat layer and a pixel definition layer that are stacked in sequence, and the active layer is disposed on the buffer layer, and the down conversion layer is disposed between the base substrate and the buffer layer. 3 . The display panel according to claim 2 , wherein when the display panel includes two down-conversion layers, another down-conversion layer is disposed between the passivation layer and the flat layer. 4 . between. 4 . The display panel according to claim 1 , further comprising a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a flat layer and a pixel definition layer that are stacked in sequence, and the down-conversion layer It is disposed on a surface of the pixel definition layer away from the flat layer. 5 . The display panel according to claim 1 , wherein the thickness of the down-conversion layer is less than or equal to 1 μm. 6 . 6. A preparation method of a display panel, wherein the preparation method comprises the following steps: providing an active layer; and A down-conversion layer is prepared, and the down-conversion layer is formed on at least one side of the active layer by spin coating or printing, and the down-conversion layer converts blue light or ultraviolet light emitted to the active layer into red light. 7 . The preparation method according to claim 6 , wherein the preparation of the down-conversion layer comprises: firstly dispersing the down-conversion luminescent material in the transparent polymer material uniformly, then dissolving in ethanol, and then performing spin coating or In the printing process, the doping concentration of the down-conversion layer is 1.5×10-5-2%, and the light absorption range is 260nm-420nm. 8 . The preparation method according to claim 7 , wherein the down-conversion luminescent material is yttrium doped europium vanadate or a rare earth complex, and the transparent polymer material is ethylene-vinyl acetate copolymer or polyvinyl alcohol. 9 . . 9 . The preparation method according to claim 6 , further comprising a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a flat layer, and a pixel definition layer formed in sequence, and the active layer is formed by forming the active layer. 10 . On the buffer layer, the down-conversion layer is formed between the base substrate and the buffer layer, and/or formed between the passivation layer and the planarization layer. 10 . The preparation method according to claim 6 , further comprising a base substrate, a buffer layer, an interlayer dielectric layer, a passivation layer, a planarization layer and a pixel definition layer formed in sequence, and the down-conversion layer is formed by 10 . on a surface of the pixel definition layer away from the flat layer.

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