KR102304198B1 - Light emitting display device - Google Patents

Abstract

A light emitting display device is provided.
For example, a light emitting display device may include a substrate on which a plurality of pixels are defined; a first electrode formed on the substrate for each pixel; a pixel defining layer partitioning each pixel on the substrate and having an opening exposing the first electrode; a charge injection layer formed on the first electrode; a surface treatment layer formed on the charge injection layer to extend from the inside of the opening of the pixel defining layer to the top surface of the pixel defining layer, the surface treatment layer having a plurality of grooves formed in the portion extending to the top surface of the pixel defining layer; a charge transport layer formed on the surface treatment layer; a light emitting layer formed on the charge transport layer; and a second electrode formed on the light emitting layer.

Description

Light-emitting display device {LIGHT EMITTING DISPLAY DEVICE}

The present invention relates to a light emitting display device and a method for manufacturing the same.

Among the light emitting display devices, the organic light emitting display device is a self-emission type display device, and has the advantage of a wide viewing angle, excellent contrast, and fast response speed.

An organic light emitting diode display includes an organic light emitting layer made of an organic light emitting material between an anode electrode and a cathode electrode. As anode and cathode voltages are respectively applied to these electrodes, holes injected from the anode electrode move to the organic light emitting layer via the hole injection layer and the hole transport layer, and electrons move from the cathode electrode to the electron injection layer and the electron transport layer. It moves to the organic light emitting layer via the way, and electrons and holes are recombined in the organic light emitting layer. An exciton is generated by this recombination, and as the exciton changes from an excited state to a ground state, the organic light emitting layer emits light, thereby displaying an image.

The organic light emitting diode display includes a pixel defining layer having an opening to expose an anode electrode formed for each pixel, and a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and electrons are disposed on the anode electrode exposed through the opening of the pixel defining layer. An injection layer and a cathode electrode are formed. Among them, the hole transport layer and the organic light emitting layer may be formed by an inkjet printing method or a nozzle printing method.

Meanwhile, a surface treatment layer having lyophilic properties may be formed on the anode electrode to improve wettability of the hole transport layer solution.

However, when the hole transport layer solution is discharged to the surface treatment layer, the hole transport layer may be undesirably spread in the direction of adjacent pixels due to the discharge pressure and the discharge speed, and the hole transport layer may be undesirably formed in a portion of the adjacent pixels. In this case, the organic light emitting layer may also be formed on a portion of adjacent pixels on the hole transport layer, so that organic light emitting layers emitting different emission colors between adjacent pixels may be formed to overlap each other.

As a result, unwanted mixed colors may be displayed when the light emitting display device is driven, and thus display quality may be deteriorated.

Accordingly, an object of the present invention is to provide a light emitting display device capable of improving display quality by preventing unwanted color mixture from being displayed.

Another object of the present invention is to provide a method of manufacturing a light emitting display device capable of improving display quality by preventing mixed colors from being displayed.

The problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a light emitting display device comprising: a substrate on which a plurality of pixels are defined; a first electrode formed on the substrate for each pixel; a pixel defining layer partitioning each pixel on the substrate and having an opening exposing the first electrode; a charge injection layer formed on the first electrode; a surface treatment layer formed on the charge injection layer to extend from the inside of the opening of the pixel defining layer to the top surface of the pixel defining layer, the surface treatment layer having a plurality of grooves formed in the portion extending to the top surface of the pixel defining layer; a charge transport layer formed on the surface treatment layer; a light emitting layer formed on the charge transport layer; and a second electrode formed on the light emitting layer.

The plurality of grooves may be located on at least one side of the opening in a first direction toward an adjacent pixel emitting a different emission color from that of the pixel on which the surface treatment layer is formed.

The plurality of grooves may have a straight shape extending in a second direction perpendicular to the first direction.

The widths of the plurality of grooves may increase toward the adjacent pixels.

Each of the plurality of grooves may have the same width.

The plurality of grooves may have an oblique shape between the first direction and a second direction perpendicular to the first direction.

The plurality of grooves may have a grid shape.

The plurality of pixels may be arranged in a row and include pixels emitting the same emission color, and the surface treatment layer may be formed to be disposed in units of the pixels.

The charge transport layer may be conformally formed along the surface treatment layer.

According to another aspect of the present invention, there is provided a light emitting display device comprising: a substrate on which a plurality of pixels are defined; a first electrode formed on the substrate for each pixel; a pixel defining layer partitioning each pixel on the substrate and having an opening exposing the first electrode; a first common layer formed on the first electrode; a surface treatment layer formed on the first common layer to extend from the inside of the opening of the pixel defining layer to the top surface of the pixel defining layer, the surface treatment layer having a plurality of grooves formed in the portion extending to the top surface of the pixel defining layer; a light emitting layer formed on the surface treatment layer; and a second electrode formed on the light emitting layer.

The plurality of grooves may be located on at least one side of the opening in a first direction toward an adjacent pixel emitting a different emission color from that of the pixel on which the surface treatment layer is formed.

The plurality of grooves may have a straight shape extending in a second direction perpendicular to the first direction.

The plurality of grooves may have an oblique shape between the first direction and a second direction perpendicular to the first direction.

The plurality of grooves may have a grid shape.

The plurality of pixels may be arranged in a row and include pixels emitting the same emission color, and the surface treatment layer may be formed to be disposed in units of the pixels.

The light emitting layer may be conformally formed along the surface treatment layer.

According to an embodiment of the present invention, there is provided a method of manufacturing a light emitting display device comprising: forming a first electrode for each pixel on a substrate on which the plurality of pixels are defined; forming a pixel defining layer partitioning each pixel on the substrate and having an opening exposing the first electrode; forming a charge injection layer on the first electrode; forming a surface treatment layer on the charge injection layer extending from the inside of the opening of the pixel defining layer to the top surface of the pixel defining layer, the surface treatment layer having a plurality of grooves in the portion extending to the top surface of the pixel defining layer; forming a charge transport layer on the surface treatment layer; forming a light emitting layer on the charge transport layer; and forming a second electrode on the light emitting layer.

The forming of the charge transport layer includes providing a charge transport layer solution into the opening of the pixel defining layer and drying the charge transport layer solution, and forming the light emitting layer into the opening of the pixel defining layer. It may include a process of providing a light emitting layer solution and a process of drying the light emitting layer solution.

The charge transport layer solution and the light emitting layer solution may include the same solvent.

The charge injection layer and the light emitting layer may be formed by an inkjet printing method or a nozzle printing method.

The details of other embodiments are included in the detailed description and drawings.

According to the embodiments of the present invention, there are at least the following effects.

The light emitting display device according to an embodiment of the present invention includes a surface treatment layer in which roughness is formed on edges through a plurality of grooves, so that the first charge transport layer solution is applied to the outside of the surface treatment layer by an inkjet printing method or a nozzle printing method. It is possible to prevent the first charge transport layer from being undesirably formed in a portion of an adjacent pixel by spreading in the direction of pixels emitting different emission colors.

Accordingly, in the light emitting display device according to the exemplary embodiment of the present invention, the light emitting layer formed on the first charge transport layer is undesirably formed in a portion of the adjacent pixels, so that the light emitting layers emitting different emission colors between the adjacent pixels PX overlap each other. By preventing the formation of , it is possible to prevent the display quality from being deteriorated due to the display of undesired mixed colors during driving.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic plan view illustrating a pixel of a light emitting display device according to an exemplary embodiment.
FIG. 2 is a cross-sectional view of a portion taken along line AA of FIG. 1 .
3 is a plan view of the surface treatment layer of FIG. 2 .
4 is a cross-sectional view illustrating a process of discharging a first charge transport layer solution to the surface treatment layer of FIG. 3 .
5 is a cross-sectional view of the first charge transport layer formed by drying the first charge transport layer solution of FIG. 4 .
6 to 12 are plan views illustrating various embodiments of a surface treatment layer.
13 is a cross-sectional view of a light emitting display device according to another exemplary embodiment.
14 is a cross-sectional view of a light emitting display device according to another exemplary embodiment.
15 is a cross-sectional view of a light emitting display device according to another exemplary embodiment.
16 to 24 are cross-sectional views illustrating a method of manufacturing a light emitting display device according to an exemplary embodiment.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

Reference to an element or layer “on” another element or layer includes any intervening layer or other element directly on or in the middle of another element. Like reference numerals refer to like elements throughout.

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic plan view illustrating a pixel of a light emitting display device according to an exemplary embodiment, and FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1 .

1 and 2 , a light emitting display device 100 according to an exemplary embodiment includes a substrate 105 , a first electrode 110 , a pixel defining layer 120 , and a first charge injection layer 130 . ), a surface treatment layer 140 , a first charge transport layer 150 , a light emitting layer 160 , a second charge transport layer 170 , a second charge injection layer 180 , and a second electrode 190 . Each member is sequentially stacked in the Z direction of FIG. 2 .

The substrate 105 includes a display area DA in which a plurality of pixels PX displaying an image are defined, and a non-display area NDA positioned outside the display area DA. The plurality of pixels PX may include a red pixel R emitting red, a green pixel G emitting green, and a blue pixel B emitting blue. In FIG. 1, it is shown that pixels PX emitting the same emission color in the Y direction are arranged in a line, and pixels PX emitting different emission colors in the X direction are alternately arranged, but with this arrangement, the present invention is not limited to

On the other hand, when the pixels PX emitting the same emission color are arranged in a line, when the first charge transport layer 150 and the emission layer 160 are formed using an inkjet printing method or a nozzle printing method, the first charge transport layer solution ( 150a) of FIG. 4 and the light emitting layer solution can be discharged in one direction, so that the discharging process can be easy. The inkjet printing method is a method of dropping a solution to be printed on a desired position in the form of ink droplets. In addition, the nozzle printing method is a method of flowing a solution to be printed along a line including a desired position.

The substrate 105 may include an insulating substrate. The insulating substrate may be formed of a transparent glass material _{including transparent SiO 2 as a main component.} In some embodiments, the insulating substrate may be made of an opaque material or a plastic material. Furthermore, the insulating substrate may be a flexible substrate.

Although not shown, the substrate 105 may further include other structures formed on the insulating substrate. Examples of the other structures include wirings, electrodes, and insulating layers. In some embodiments, the substrate 105 may include a plurality of thin film transistors formed on an insulating substrate. A drain electrode of at least a portion of the plurality of thin film transistors may be electrically connected to the first electrode 110 . The thin film transistor may include an active region made of amorphous silicon, polycrystalline silicon, or single crystal silicon. In another embodiment, the thin film transistor may include an active region formed of an oxide semiconductor.

The first electrode 110 is formed for each pixel PX on the substrate 105 . The first electrode 110 may be an anode electrode that receives a signal applied to the drain electrode of the thin film transistor and provides holes to the emission layer 160 or a cathode electrode that provides electrons. The first electrode 110 may be used as a transparent electrode or a reflective electrode. When the first electrode 110 is used as a transparent electrode, it may be formed of indium tin oxide (ITO), ITO zinc oxide (IZO), zinc oxide (ZnO), or In ₂ O ₃ . And, when the first electrode 110 is used as a reflective electrode, after forming a reflective film with Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and a compound thereof, ITO, IZO thereon , ZnO or In ₂ O ₃ may be formed to form. The first electrode 110 may be formed through a photolithography process, but is not limited thereto.

The pixel defining layer 120 partitions each pixel PX on the substrate 105 and has an opening OP exposing the first electrode 110 . Accordingly, the pixel defining layer 120 causes the first charge injection layer 130 to be formed on the first electrode 110 through the opening OP. The pixel defining layer 120 may be made of an insulating material. Specifically, the pixel defining layer 120 may include at least one organic selected from benzocyclobutene (BCB), polyimide (PI), polyamide (PA), acrylic resin, and phenolic resin. It may include a material. Also, as another example, the pixel defining layer 120 may include an inorganic material such as silicon nitride. The pixel defining layer 120 may be formed through a photolithography process, but is not limited thereto.

In an embodiment of the present invention, the pixel defining layer 120 is formed by using a first charge transport layer solution ( It may be formed of an insulating material that makes the contact angle of 150a of FIG. 4 different from the contact angle of the first charge transport layer solution ( 150a of FIG. 4 ) with respect to the surface treatment layer 140 . Specifically, in the pixel defining layer 120 , the contact angle of the first charge transport layer solution with respect to the pixel defining layer 120 ( 150a of FIG. 4 ) is the first charge transport layer solution with respect to the surface treatment layer 140 ( 150a of FIG. 4 ). ) may be formed of an insulating material that can be made larger than the contact angle. For example, the pixel defining layer 120 may be formed of an insulating material such that the contact angle of the first charge transport layer solution ( 150a of FIG. 4 ) with respect to the pixel defining layer 120 is 40° or more.

The first charge injection layer 130 may be formed on the first electrode 110 exposed through the opening OP of the pixel defining layer 120 , and may be formed to cover all of the pixel defining layer 120 . The first charge injection layer 130 may be a hole injection layer receiving holes from the first electrode 120 or an electron injection layer receiving electrons. In the embodiment of the present invention, the first charge injection layer 130 will be described as an example of a hole injection layer. The first charge injection layer 130 is a buffer layer that lowers the energy barrier between the first electrode 110 and the first charge transport layer 150 , and holes provided from the first electrode 110 are transferred to the first charge transport layer 150 . It serves to facilitate injection. The first charge injection layer 130 is formed of an organic compound, for example, MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), CuPc (copper phthalocyanine), or PEDOT/PSS (poly(3,4-) It may be made of ethylenedioxythiphene, polystyrene sulfonate, etc., but is not limited thereto. The first charge injection layer 130 may be formed through slit coating, but is not limited thereto.

The surface treatment layer 140 is formed for each pixel PX on the first charge injection layer 130 . Specifically, the surface treatment layer 140 is formed on the first charge injection layer 130 to extend from the inside of the opening OP of the pixel defining layer 120 to the top surface of the pixel defining layer 120 . It is formed to have a plurality of grooves g1 in the portion extending to the upper surface of the 120 . The surface treatment layer 140 may be formed through a photolithography process, but is not limited thereto.

The surface treatment layer 140 is more lyophilic than the pixel defining layer 120 with respect to the first charge transport layer solution (150a in FIG. 4 ), that is, the first charge transport layer solution for the surface treatment layer 140 ( FIG. 4 ). 150a) may be formed of a conductive primer that is smaller than a contact angle of the first charge transport layer solution (150a of FIG. 4 ) with respect to the pixel defining layer 120 . For example, the surface treatment layer 140 may be formed of a conductive primer having a contact angle of 20° or less between the first charge transport layer solution ( 150a in FIG. 4 ) with respect to the surface treatment layer 140 . In this case, the first charge transport layer solution ( 150a of FIG. 4 ) is applied to the plurality of pixels PX by using an inkjet printing method or a nozzle printing method to the surface treatment layer 140 inside the opening OP of the pixel defining layer 120 . ), the wettability of the first charge transport layer solution (150a in FIG. 4) with respect to the surface treatment layer 140 is high when discharged onto the pixel defining layer 120 to which the first charge transport layer solution (150a in FIG. 4) is exposed. may be stably confined within the corresponding pixel without spreading to the upper surface of the , and the first charge transport layer 150 may be uniformly formed on the surface treatment layer 140 . The high wettability may mean that the liquid spreads widely on the solid surface and the degree of contact is high. A more detailed description of the surface treatment layer 140 will be described later.

The first charge transport layer 150 is formed on the surface treatment layer 140 . The first charge transport layer 150 may be conformally formed along the surface treatment layer 140 having the plurality of grooves g1 . The first charge transport layer 150 at least partially fills the groove g1 of the surface treatment layer 140 .

The first charge transport layer 150 may be a hole transport layer receiving holes from the first charge injection layer 130 through the surface treatment layer 140 or an electron transport layer receiving electrons. In the embodiment of the present invention, the first charge transport layer 130 will be described as an example of a hole transport layer. The first charge transport layer 150 serves to transfer holes provided from the first charge injection layer 130 through the surface treatment layer 140 to the emission layer 160 . The first charge transport layer 150 is an organic compound, for example, TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-bi-phenyl-4,4'- diamine) or NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), but is not limited thereto. The first charge transport layer 150 may be formed using an inkjet printing method or a nozzle printing method, but is not limited thereto.

The emission layer 160 is formed on the first charge transport layer 150 . The light emitting layer 160 emits light by recombination of holes provided from the first electrode 110 and electrons provided from the second electrode 190 . More specifically, when holes and electrons are provided to the emission layer 160 , the holes and electrons combine to form excitons, and the excitons change from an excited state to a ground state to emit light. The emission layer 160 may include a red emission layer emitting red light, a green emission layer emitting green light, and a blue emission layer emitting blue color. The light emitting layer 160 may be formed using an inkjet printing method or a nozzle printing method, but is not limited thereto.

The red emission layer may include one red emission material or may include a host and a red dopant. Examples of the host of the red light emitting layer include Alq ₃ , CBP (4,4'-N,N'-dicarbazol-biphenyl), PVK (ploy (n-vinylcarbaxol)), ADN (9,10-Di (naphthyl-2- yl)anthrace), TCTA, TPBI(1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene), TBADN(3-tert-butyl-9,10-di(naphth-2-yl) anthracene) , E3, DSA (distyrylarylene), etc. may be used, but the present invention is not limited thereto. In addition, as the red dopant, PtOEP, Ir(piq) ₃ , Btp ₂ Ir(acac), etc. may be used, but is not limited thereto.

The green light emitting layer may include one green light emitting material or may include a host and a green dopant. The host of the red light emitting layer may be used as the host of the green light emitting layer. In addition, as the green dopant, Ir(ppy) ₃ , Ir(ppy) ₂ (acac), Ir(mpyp) _{3 ,} etc. may be used, but is not limited thereto.

The blue light emitting layer may include one blue light emitting material or may include a host and a blue dopant. As the host of the blue light emitting layer, the host of the red light emitting layer may be used. And, as the blue dopant, F ₂ Irpic, (F ₂ ppy) ₂ Ir(tmd), Ir(dfppz) ₃ , ter-fluorene, DPAVBi(4,4'-bis(4-diphenylaminostyryl) biphenyl), TBPe ( 2,5,8,11-tetra-ti-butyl pherylene) may be used, but is not limited thereto.

The second charge transport layer 170 is formed on the light emitting layer 160 and may be an electron transport layer receiving electrons from the second electrode 190 through the second charge injection layer 180 or a hole transport layer receiving holes. . In the embodiment of the present invention, the second charge transport layer 170 will be described as an electron transport layer as an example. The second charge transport layer 170 serves to transfer electrons provided from the second electrode 190 through the second charge injection layer 180 to the emission layer 160 . The second charge transport layer 170 is an organic compound, for example, Bphen(4,7-diphenyl-1,10-phenanthroline)), BAlq, Alq3 (Tris(8-quinolinorate)aluminum), Bebq ₂ (berylliumbis(benzoquinolin)). -10-olate), TPBI, etc. may be used, but is not limited thereto The second charge transport layer 170 may be formed through a deposition process, etc., but is not limited thereto.

The second charge injection layer 180 is formed on the second charge transport layer 170 and may be an electron injection layer receiving electrons from the second electrode 190 or a hole injection layer receiving holes. In the embodiment of the present invention, the second charge injection layer 180 will be described as an electron injection layer as an example. The second charge injection layer 180 is a buffer layer that lowers the energy barrier between the second charge transport layer 170 and the second electrode 190 , and electrons provided from the second electrode 190 are transferred to the second charge transport layer 170 . It serves to facilitate injection. The second charge injection layer 180 may be formed of, for example, LiF or CsF, but is not limited thereto. The second charge injection layer 180 may be formed through a deposition process, but is not limited thereto.

The second electrode 190 is formed on the second charge injection layer 180 , and may be a cathode electrode providing electrons to the emission layer 160 or an anode electrode providing holes. Like the first electrode 110 , the second electrode 190 may be used as a transparent electrode or a reflective electrode. The second electrode 190 may be formed through a deposition process or the like, but is not limited thereto.

Although not shown, the light emitting display device 100 may further include an encapsulation substrate disposed on the second electrode 190 . The encapsulation substrate may be formed of an insulating substrate. A spacer may be disposed between the second electrode 190 on the pixel defining layer 120 and the encapsulation substrate. In some other embodiments of the present invention, the encapsulation substrate may be omitted. In this case, an encapsulation film made of an insulating material may cover and protect the entire structure.

Next, the surface treatment layer 140 will be described in more detail.

FIG. 3 is a plan view of the surface treatment layer of FIG. 2 , FIG. 4 is a cross-sectional view showing a process of discharging the first charge transport layer solution to the surface treatment layer of FIG. 3 , and FIG. 5 is the charge transport layer solution of FIG. 4 formed by drying A cross-sectional view of the first charge transport layer.

Referring to FIG. 3 , the surface treatment layer 140 is formed to have a plurality of grooves g1 on at least one side thereof, and the plurality of grooves g1 may be disposed on at least one side of the opening of the pixel defining layer. The one side or the direction of one side may be the first direction D1 toward the adjacent pixel PX emitting an emission color different from the emission color of the corresponding pixel PX in which the surface treatment layer 140 is formed. For example, when a red pixel R emitting red and a green pixel G emitting green are adjacent to each other, the red pixel G is disposed in the surface treatment layer 140 formed on the red pixel R It has a plurality of grooves (g1) on one side of the direction. In FIG. 3 , for example, a plurality of grooves g1 are formed on both sides of the surface treatment layer 140 when pixels PX emitting different emission colors are disposed on both sides of one pixel PX as an example. was shown to be

The plurality of grooves g1 may have a straight shape extending in a first direction D1 and a second direction D2 perpendicular to the adjacent pixel PX. The plurality of grooves g1 form roughness at the edge of the surface treatment layer 140 . Accordingly, the surface treatment layer 140 discharges the first charge transport layer solution 150a through the plurality of grooves g1 from the discharge device 10 to the surface treatment layer 140 using, for example, a nozzle printing method. to increase the contact angle of the first charge transport layer solution 150a with respect to the edge of the surface treatment layer 140 to prevent the first charge transport layer solution 150a from escaping to the outside of the surface treatment layer 140 One charge transport layer solution 150a may be confined in the plurality of grooves g1 .

That is, when the first charge transport layer solution 150a is discharged from the discharge device 10 through the plurality of grooves g1 , the surface treatment layer 140 is formed outside the surface treatment layer 140 by the discharge pressure and discharge speed. The first charge transport layer solution 150a is inserted into the plurality of grooves g1 while preventing the first charge transport layer solution 150a from escaping to the outside of the surface treatment layer 140 by increasing the resistance to the force F spreading to the ) can be confined to Accordingly, it is possible to prevent the first charge transport layer solution 150a from flowing in the direction of the adjacent pixel PX, for example, the pixel PX emitting a different emission color, and from spreading undesirably to a portion of the adjacent pixel PX.

The widths w1 , w2 , and w3 of each of the plurality of grooves g1 may increase toward the adjacent pixel PX. In this case, the plurality of grooves g1 prevents an abrupt increase in the contact angle of the first charge transport layer solution 150a with respect to the edge of the surface treatment layer 140 , so that the first charge transport layer solution 150a is surface treated. It can be spread over a large area on the layer 140 . Accordingly, when the first charge transport layer solution 150a discharged on the surface treatment layer 140 is dried to form the first charge transport layer 150 as shown in FIG. 5 , the first charge transport layer 150 . A large area may be formed on the surface treatment layer 140 .

Meanwhile, the first charge transport layer 150 formed by drying the first charge transport layer solution 150a forms a pinning point P with the surface treatment layer 140 as shown in FIG. 5 . In this case, the light emitting layer 160 is formed by discharging and drying the light emitting layer solution containing the same solvent as the solvent of the first charge transport layer solution 150a on the first charge transport layer 150 by an inkjet printing method or a nozzle printing method. It is formed according to this pinning point P. That is, the edge of the light emitting layer 160 coincides with the edge of the first charge transport layer 150 .

6 to 12 are plan views illustrating various embodiments of a surface treatment layer.

6 illustrates that the surface treatment layer 140a is formed to have a plurality of grooves g2 having a lattice shape on at least one side thereof. The plurality of grooves g2 includes first grooves g21 having a straight shape extending in a second direction D2 perpendicular to a first direction D1 toward an adjacent pixel PX, and a first direction D1 . The second grooves g22 having a straight shape extending to are formed to be orthogonal to each other. Here, the width of the first grooves g21 may increase in the first direction D1.

The plurality of grooves g2 move the discharge device 10 to discharge the first charge transport layer solution to the surface treatment layer 140a by discharging the first charge transport layer solution to the outside of the surface treatment layer 140a. ) is generated in the first direction D1 and in the diagonal direction between the first direction D1 and the second direction D2, the first charge transport layer solution escapes in the diagonal direction as well as in the first direction D1. can be effectively prevented.

7 illustrates that the surface treatment layer 140b is formed to have a plurality of grooves g3 having a diagonal shape on at least one side thereof. It is exemplified that the plurality of grooves g3 are formed to have an oblique shape between a first direction D1 facing the adjacent pixel PX and a second direction D2 perpendicular to the first direction D1. Here, the width of each of the plurality of grooves g3 may be the same.

When the plurality of grooves g3 also move the discharging device 10 to discharge the first charge transport layer solution to the surface treatment layer 140b, the force F that the first charge transport layer solution spreads to the outside of the surface treatment layer 140b ) is generated in the diagonal direction between the first direction D1 and the first direction D1 and the second direction D2, effectively preventing deviation in the diagonal direction as well as in the first direction D1. have.

FIG. 8 illustrates that the surface treatment layer 140c is formed to have a plurality of grooves g4 having oblique shapes in different directions on one side and the other side. That is, the plurality of grooves g4 are first grooves having a first oblique shape between a first direction D1 toward an adjacent pixel PX and a second direction D2 perpendicular to the first direction D1. It includes ( g41 ) and second grooves ( g42 ) having a second diagonal shape symmetrical to the first diagonal shape with respect to the second direction ( D2 ).

The first oblique shape is the force (F) by which the first charge transport layer solution spreads to the outside of the surface treatment layer 140c when the discharging device 10 is moved to discharge the first charge transport layer solution to the surface treatment layer 140c. ) is generated in a diagonal direction between the first direction D1 and the second direction D2 on one side of the surface treatment layer 140c, and has an oblique shape perpendicular to the diagonal direction. Accordingly, in the first grooves g41 having the first oblique shape, the first charge transport layer solution is formed in a diagonal direction between the first direction D1 and the second direction D2 on one side of the surface treatment layer 140c. can be effectively prevented from escaping.

The second oblique shape is the force (F) by which the first charge transport layer solution spreads to the outside of the surface treatment layer 140c when the discharge device 10 is moved to discharge the first charge transport layer solution to the surface treatment layer 140c. ) is generated in the diagonal direction between the first direction D1 and the second direction D2 from the other side of the surface treatment layer 140c, and has a diagonal shape perpendicular to the diagonal direction. Accordingly, in the second grooves g42 having the second oblique shape, the first charge transport layer solution is formed in the diagonal direction between the first direction D1 and the second direction D2 at the other side of the surface treatment layer 140c. can be effectively prevented from escaping.

The plurality of grooves g3 move the discharge device 10 to discharge the first charge transport layer solution to the surface treatment layer 140c, causing the first charge transport layer solution to spread outward of the surface treatment layer 140c (F). ) is generated in the diagonal direction between the first direction D1 and the second direction D2, it is possible to effectively prevent the first charge transport layer solution from being separated in different diagonal directions.

9 shows that the surface treatment layer 140d is formed to have a plurality of grooves g5 having a lattice shape in which first diagonal grooves g51 and diagonal second grooves g52 are orthogonal to each other on at least one side thereof. foreshadows to be

In the plurality of grooves g5 , the first charge transport layer solution flows in a diagonal direction between the first direction D1 and the second direction D2 as well as in the first direction D1 even if the movement start point of the discharge device 10 is different. can be effectively prevented from escaping.

10 illustrates that the surface treatment layer 140e is formed to have a plurality of grooves g6 having the same width on at least one side thereof. The surface treatment layer 140e having the plurality of grooves g6 may be advantageously applied when there is a limitation in the formation space, for example, when the pitch between adjacent pixels PX is fine.

11 illustrates that the surface treatment layer 140f is arranged in a line and is formed in units of pixels PX emitting the same emission color. For example, the surface treatment layer 140f is formed in units of at least two pixels PX or more and has a larger size than the surface treatment layer 140 of FIG. 3 , but is different in the same shape as the surface treatment layer 140 . It is formed to have a plurality of grooves g7 extending in a first direction D1 and a second direction D2 perpendicular to the adjacent pixel PX emitting the emission color. When the surface treatment layer 140f is formed through a photolithography process, a patterning process may be facilitated.

12 illustrates that the surface treatment layer 140g is formed to have a plurality of grooves g8 on all side surfaces. The plurality of grooves g8 are formed in the same shape as the plurality of grooves g1 of the surface treatment layer 140 of FIG. 3 . The plurality of grooves g8 is formed by applying the first charge transport layer solution onto the surface treatment layer 140g by an inkjet printing method when pixels X emitting different emission colors are disposed in all directions based on one pixel PX. It is possible to prevent the first charge transport layer solution from escaping to all directions of the surface treatment layer 140g when discharging to the .

As described above, the light emitting display device according to the embodiments of the present invention includes the surface treatment layers 140 and 140a to 140g in which roughness is formed on the edges through the plurality of grooves g1 to g8, so that the inkjet printing method or the nozzle is used. When the first charge transport layer solution 150a is discharged to the surface treatment layers 140 and 140a to 140g by the printing method, the first charge transport layer solution 150a is transferred to the surface treatment layer 140 by the discharge pressure and discharge speed. It is possible to prevent the first charge transport layer solution 150a from escaping to the outside of the surface treatment layer 140 by increasing the resistance to the force F spreading outward.

Accordingly, in the light emitting display device according to the embodiments of the present invention, the first charge transport layer solution 150a spreads in the direction of the adjacent pixel PX, for example, the pixel PX emitting different emission colors to the first charge transport layer ( It is possible to prevent the undesirable formation of the 150 , even in a portion of the adjacent pixel PX.

Accordingly, in the light emitting display device according to embodiments of the present invention, the light emitting layer 160 is formed on the first charge transport layer 150 to a portion of the adjacent pixel PX to emit different emission colors between the adjacent pixels PX. By preventing the light emitting layers from being overlapped with each other, it is possible to prevent the display quality from being deteriorated due to the display of unwanted mixed colors during driving.

13 is a cross-sectional view of a light emitting display device according to another exemplary embodiment.

Referring to FIG. 13 , the light emitting display device 200 according to another embodiment of the present invention has the same configuration as that of the light emitting display device 100 of FIG. 2 except that only the first charge transport layer 250 and the light emitting layer 260 are different. have Accordingly, in the light emitting display device 200 according to another embodiment of the present invention, only the first charge transport layer 250 and the light emitting layer 260 will be described.

The first charge transport layer 250 is similar to the first charge transport layer 150 of FIG. 2 . However, the first charge transport layer 250 is not formed on the surface treatment layer 140 to the edge of the surface treatment layer 140 , but is formed to be accommodated in a portion of the plurality of grooves g1 . In this structure, when the discharge pressure is low when the first charge transport layer solution is discharged onto the surface treatment layer 140 by the inkjet printing method or the nozzle printing method to form the first charge transport layer 250, the surface treatment layer 140 It can be formed by not spreading to the edge of

The emission layer 260 is similar to the emission layer 160 of FIG. 2 . However, the emission layer 260 is formed on the first charge transport layer 250 and extends to the edge of the surface treatment layer 140 . Such a structure may be formed by having the surface treatment layer 140 have lyophilicity not only to the first charge transport layer solution 150a but also to the light emitting layer solution when the solvent of the light emitting layer solution is the same as the solvent of the first charge transport layer solution.

Meanwhile, although not shown, the plurality of grooves g2 to g7 shown in FIGS. 6 to 12 may be applied to the plurality of grooves g1 of the surface treatment layer 140 .

As described above, the light emitting display device 200 according to another embodiment of the present invention includes the surface treatment layer 140 having a plurality of grooves g1 on at least one side like the light emitting display device 100 , so that the first charge The emission layer 260 is formed on the transport layer 250 to a portion of the adjacent pixels PX to prevent the emission layers emitting different emission colors from being overlapped with each other between the adjacent pixels PX, thereby preventing unwanted color mixture during driving. It is possible to prevent display quality from being displayed.

14 is a cross-sectional view of a light emitting display device according to another exemplary embodiment.

Referring to FIG. 14 , the light emitting display device 300 according to another embodiment of the present invention is the same as compared to the light emitting display device 100 of FIG. 2 except that only the first charge transport layer 350 and the light emitting layer 360 are different. have a configuration Accordingly, in the light emitting display device 300 according to another embodiment of the present invention, only the first charge transport layer 350 and the light emitting layer 360 will be described.

The first charge transport layer 350 is similar to the first charge transport layer 150 of FIG. 2 . However, the first charge transport layer 350 is formed on the surface treatment layer 140 , but is not formed on the surface treatment layer 140 between the plurality of grooves g1 . That is, the height of the first charge transport layer 350 in the plurality of grooves g1 may be less than or equal to the height of the plurality of grooves g1 . In this structure, in order to form the first charge transport layer 350, the first charge transport layer solution is discharged onto the surface treatment layer 140 by an inkjet printing method or a nozzle printing method, and then a plurality of layers of the surface treatment layer 140 are dried. It may be formed by drying the first charge transport layer solution in a portion of the groove g1.

The emission layer 360 is similar to the emission layer 160 of FIG. 2 . However, the light emitting layer 360 is formed on the first charge transport layer 350 and is in contact with the surface treatment layer 140 in the plurality of grooves g1 of the surface treatment layer 140 . Such a structure may be formed by having the surface treatment layer 140 have lyophilicity not only to the first charge transport layer solution 150a but also to the light emitting layer solution when the solvent of the light emitting layer solution is the same as the solvent of the first charge transport layer solution.

Meanwhile, although not shown, the plurality of grooves g2 to g7 shown in FIGS. 6 to 12 may be applied to the plurality of grooves g1 of the surface treatment layer 140 .

As described above, the light emitting display device 300 according to another embodiment of the present invention includes the surface treatment layer 140 having a plurality of grooves g1 on at least one side like the light emitting display device 100 , so that the first The light emitting layer 360 is formed on a portion of the adjacent pixels PX on the charge transport layer 350 to prevent the light emitting layers emitting different emission colors between the adjacent pixels PX from being overlapped with each other. It is possible to prevent deterioration of display quality by displaying mixed colors.

15 is a cross-sectional view of a light emitting display device according to another exemplary embodiment.

Referring to FIG. 15 , a light emitting display device 400 according to another exemplary embodiment includes a substrate 105 , a first electrode 110 , a pixel defining layer 420 , a first common layer 430 , and a surface. It includes a processing layer 440 , an emission layer 450 , a second common layer 460 , and a second electrode 470 .

Since the substrate 105 and the first electrode 110 have been described in detail in the previous embodiment, a redundant description will be omitted.

The pixel defining layer 420 is similar to the pixel defining layer 120 of FIG. 2 . However, when the light emitting layer 450 is formed by using the inkjet printing method or the nozzle printing method, the pixel defining layer 420 has a contact angle of the light emitting layer solution with respect to the pixel defining layer 420 and the light emitting layer solution with respect to the surface treatment layer 440 . may be formed of an insulating material that allows different contact angles of the . Specifically, the pixel defining layer 420 may be formed of an insulating material capable of making the contact angle of the light emitting layer solution with respect to the pixel defining layer 420 greater than the contact angle of the light emitting layer solution with the surface treatment layer 440 . For example, the pixel defining layer 420 may be formed of an insulating material such that a contact angle of the light emitting layer solution with respect to the pixel defining layer 420 is 40° or more.

The first common layer 430 is formed on the first electrode 110 exposed through the opening OP of the pixel defining layer 420 , and may be formed to cover all of the pixel defining layer 420 . The first common layer 430 includes a first charge injection layer. The first charge injection layer contacts the first electrode 110 . Also, the first common layer 430 may further include a first charge transport layer disposed on the first charge injection layer. The first charge injection layer and the first charge transport layer may be formed of the same material as the first charge injection layer 130 and the first charge transport layer 140 of FIG. 2 .

The surface treatment layer 440 has a plurality of grooves g1 on at least one side thereof, and is similar to the surface treatment layer 140 of FIG. 2 . However, the surface treatment layer 440 is more lyophilic to the light emitting layer solution than the pixel defining layer 420 , that is, the contact angle of the light emitting layer solution with respect to the surface treatment layer 440 is the light emitting layer solution with respect to the pixel defining layer 420 . It may be formed of a conductive primer that is smaller than the contact angle of . For example, the surface treatment layer 440 may be formed of a conductive primer having a contact angle of the light emitting layer solution with respect to the surface treatment layer 440 of 20° or less. In this case, when the light emitting layer solution is discharged onto the surface treatment layer 440 inside the opening OP of the pixel defining layer 420 by using the inkjet printing method or the nozzle printing method on the plurality of pixels PX, the surface treatment layer Due to the high wettability of the light emitting layer solution with respect to 440 , the light emitting layer solution can be stably confined in the corresponding pixel without spreading to the upper surface of the exposed pixel defining layer 420 , and the light emitting layer 450 is formed on the surface treatment layer 440 . can be uniformly formed.

The emission layer 450 is similar to the emission layer 160 of FIG. 2 . However, the emission layer 450 is formed on the surface treatment layer 440 . The emission layer 450 may be conformally formed along the surface treatment layer 440 having a plurality of grooves g1 forming roughness. The emission layer 450 at least partially fills the groove g1 of the surface treatment layer 440 .

Since the light emitting layer 450 is directly formed on the surface treatment layer 440 , when the light emitting layer solution is discharged to the surface treatment layer 440 using a nozzle printing method to form the light emitting layer 450 , the surface treatment layer 440 . ) may be confined in the plurality of grooves g1 of the surface treatment layer 440 while preventing the light emitting layer solution from being separated to the outside of the surface treatment layer 440 by increasing the contact angle of the light emitting layer solution with respect to the edge of the surface treatment layer 440 .

The second common layer 460 is formed on the emission layer 450 . The second common layer 460 includes a second charge transport layer. The second charge transport layer is in contact with the light emitting layer 460 . Also, the second common layer 430 may further include a second charge injection layer disposed on the second charge transport layer. The second charge transport layer and the second charge injection layer may be formed of the same material as the second charge transport layer 170 and the second charge injection layer 180 of FIG. 2 .

The second electrode 470 is the same as the second electrode 190 of FIG. 2 . Accordingly, redundant descriptions will be omitted.

Meanwhile, although not shown, the plurality of grooves g2 to g7 illustrated in FIGS. 6 to 12 may be applied to the plurality of grooves g1 of the surface treatment layer 440 .

As described above, the light emitting display device 400 according to another embodiment of the present invention includes a surface treatment layer 440 having a plurality of grooves g1 on at least one side, similar to the light emitting display device 100 , thereby surface treatment. The emission layer 450 is formed on a portion of the adjacent pixels PX on the layer 440 to prevent the emission layers emitting different emission colors from overlapping each other between the adjacent pixels PX, thereby preventing unwanted color mixture during driving. It is possible to prevent display quality from being displayed.

Hereinafter, an exemplary method for manufacturing the light emitting display device according to various embodiments of the present invention described above will be described.

16 to 24 are cross-sectional views illustrating a method of manufacturing a light emitting display device according to an exemplary embodiment.

Referring to FIG. 16 , a first electrode 110 for each pixel is formed on a substrate 105 on which a plurality of pixels (PX in FIG. 1 ) are defined. The first electrode 110 may be formed by depositing and patterning a transparent electrode material or a reflective material on the substrate 105 .

Next, referring to FIG. 17 , a pixel defining layer 120 partitioning each pixel (PX in FIG. 1 ) and having an opening OP exposing the first electrode 110 is formed on the substrate. The pixel defining layer 120 may be formed by depositing an insulating material on the entire surface of the substrate 105 using a deposition method to cover the first electrode 110 and patterning the deposited insulating material.

On the other hand, when the first charge transport layer 150 is formed using an inkjet printing method or a nozzle printing method, the pixel defining layer 120 is formed of the first charge transport layer solution (150a in FIG. 20 ) for the pixel defining layer 120 . The contact angle and the contact angle of the first charge transport layer solution (150a of FIG. 20) with respect to the surface treatment layer (140 of FIG. 19) may be formed of an insulating material that can be different. For example, the pixel defining layer 120 may be formed of an insulating material such that a contact angle of the first charge transport layer solution ( 150a of FIG. 20 ) with respect to the pixel defining layer 120 is 40° or more.

Next, referring to FIG. 18 , a first charge injection layer 130 is formed on the first electrode 110 . The first charge injection layer 130 may be formed on the entire surface of the pixel defining layer 120 as well as the first electrode 110 by using a slit coating or the like.

Then, referring to FIG. 19 , a plurality of portions extending from the inside of the opening OP of the pixel defining layer 120 to the top surface of the pixel defining layer 120 on the first charge injection layer 130 are formed on the top surface of the pixel defining layer 120 . A surface treatment layer 140 having a groove g1 is formed. The surface treatment layer 140 may be formed using a photolithography process. The surface treatment layer 140 may be formed in the shape shown in FIG. 3 . Of course, the plurality of grooves g1 of the surface treatment layer 140 may be formed of the plurality of grooves g2 to g8 shown in FIGS. 6 to 13 .

On the other hand, the surface treatment layer 140 is more lyophilic than the pixel defining layer 120 with respect to the first charge transport layer solution (150a in FIG. 4 ), that is, the first charge transport layer solution ( The conductive primer may be formed so that the contact angle of 150a of FIG. 4 is smaller than the contact angle of the first charge transport layer solution ( 150a of FIG. 4 ) with respect to the pixel defining layer 120 . For example, the surface treatment layer 140 may be formed of a conductive primer having a contact angle of 20° or less between the first charge transport layer solution ( 150a in FIG. 4 ) with respect to the surface treatment layer 140 . In this case, the first charge transport layer solution ( 150a of FIG. 4 ) is applied to the plurality of pixels PX by using an inkjet printing method or a nozzle printing method to the surface treatment layer 140 inside the opening OP of the pixel defining layer 120 . ), the wettability of the first charge transport layer solution (150a in FIG. 4) with respect to the surface treatment layer 140 is high when discharged onto the pixel defining layer 120 to which the first charge transport layer solution (150a in FIG. 4) is exposed. may be stably confined within the corresponding pixel without spreading to the upper surface of the , and the first charge transport layer 140 may be uniformly formed on the surface treatment layer 140 .

20 and 21 , the first charge transport layer 150 is formed on the surface treatment layer 140 .

Referring to FIG. 20 , the first charge transport layer solution 150a is discharged from the discharge device 10 by an inkjet printing method or a nozzle printing method and provided inside the opening OP of the pixel defining layer 120 . At this time, the force F that the first charge transport layer solution 150a spreads out of the surface treatment layer 140 due to the discharge pressure and the discharge speed is large, so that the first charge transport layer solution 150a is applied to the surface treatment layer 140 . ) may deviate from the edge of the However, the surface treatment layer 140 increases the resistance to the force F through the plurality of grooves g1 that form roughness at the edges, so that the first charge transport layer solution 150a is formed of the surface treatment layer 140 . The first charge transport layer solution 150a may be confined in the plurality of grooves g1 while preventing it from escaping to the outside.

And, referring to FIG. 21 , the first charge transport layer 150 is dried to form the surface treatment layer 140 and the pinning point P on the surface treatment layer 140 by drying the first charge transport layer solution 150a. to form The first charge transport layer 150 may be conformally formed along the surface treatment layer 140 having the plurality of grooves g1 .

Next, referring to FIGS. 22 and 23 , the emission layer 160 is formed on the first charge transport layer 150 .

Referring to FIG. 22 , the light emitting layer solution 160a is discharged from the discharge device 20 by an inkjet printing method or a nozzle printing method and provided inside the opening OP of the pixel defining layer 120 . In this case, the light emitting layer solution 160a may include the same solvent as the first charge transport layer solution 150a of FIG. 20 . In this case, the first charge transport layer 150 may have lyophilicity with respect to the light emitting layer solution 160a, and when the light emitting layer solution 160a is discharged to the first charge transport layer 150, the outer side of the first charge transport layer 150 It is possible to prevent the phosphorus from being separated from the exposed top surface of the pixel defining layer 120 .

Then, referring to FIG. 23 , the light emitting layer 160 is formed on the first charge transport layer 150 by drying the light emitting layer solution 160a.

Next, referring to FIG. 24 , a second charge transport layer 170 , a second charge injection layer 180 , and a second electrode 190 are formed on the emission layer 160 . The second charge transport layer 170 , the second charge injection layer 180 , and the second electrode 190 may be formed through a deposition process.

Although not shown, the method of manufacturing a light emitting display device according to an exemplary embodiment may further include disposing an encapsulation substrate on the second electrode 190 . Also, the method of manufacturing a light emitting display device according to an exemplary embodiment may further include disposing a spacer between the second electrode 190 and the encapsulation substrate. Since various methods of disposing the encapsulation substrate and disposing the spacers are well known in the art, a detailed description thereof will be omitted.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100, 200, 300, 440: light emitting display device 105: substrate
110: first electrode 120: pixel defining layer
130: first charge injection layer
140, 140a, 140b, 140c, 140d, 140e, 140f, 140g: surface treatment layer
150: first charge transport layer 160, 450: light emitting layer
170: second charge transport layer 180: second charge injection layer
190, 470: second electrode 430: first common layer
460: second common layer

Claims (15)

Board;
a first electrode positioned on the substrate;
a pixel defining layer having an opening exposing the first electrode and positioned on the substrate;
a surface treatment layer including a first portion on the first electrode and a second portion on the pixel defining layer;
a charge transport layer formed on the surface treatment layer;
a light emitting layer formed on the charge transport layer; and
a second electrode formed on the light emitting layer;
the second portion of the surface treatment layer includes a plurality of grooves that do not overlap the openings of the pixel defining layer;
A portion of the charge transport layer is located inside at least one of the plurality of grooves,
A pinning point is defined between the charge transport layer and the surface treatment layer,
an end of the charge transport layer and an end of the surface treatment layer are aligned with the pinning point. delete According to claim 1,
The first portion of the surface treatment layer extends from the second portion of the surface treatment layer. According to claim 1,
The plurality of grooves are positioned on at least one side of the opening in a first direction toward an adjacent pixel emitting an emission color different from that of the pixel on which the surface treatment layer is formed. 5. The method of claim 4,
The plurality of grooves have a linear shape extending in a second direction perpendicular to the first direction. 5. The method of claim 4,
A width of the plurality of grooves increases toward the adjacent pixels. 5. The method of claim 4,
Each of the plurality of grooves has the same width. 5. The method of claim 4,
The plurality of grooves have an oblique shape between the first direction and a second direction perpendicular to the first direction. 5. The method of claim 4,
The plurality of grooves have a grid shape. Board;
a first electrode positioned on the substrate;
a pixel defining layer having an opening exposing the first electrode and positioned on the substrate;
a surface treatment layer including a first portion on the first electrode and a second portion on the pixel defining layer;
a charge transport layer formed on the surface treatment layer;
a light emitting layer formed on the charge transport layer; and
a second electrode formed on the light emitting layer;
the second portion of the surface treatment layer includes a plurality of grooves that do not overlap the openings of the pixel defining layer;
A portion of the charge transport layer is located inside at least one of the plurality of grooves,
The plurality of grooves are located on at least one side of the opening along a first direction toward an adjacent pixel emitting a luminous color different from that of the pixel on which the surface treatment layer is formed, and the surface treatment layer is a unit of pixels emitting the same luminous color. placed within,
A plurality of units of the pixels are arranged in a second direction. 11. The method of claim 10,
The plurality of grooves have a linear shape extending along the second direction,
The pixels emitting the same emission color are positioned between two of the plurality of grooves along the first direction. According to claim 1,
The charge transport layer is conformally formed along a surface of the surface treatment layer. According to claim 1,
and a charge injection layer disposed between the first electrode and the surface treatment layer. 14. The method of claim 13,
the plurality of grooves expose a portion of the charge injection layer;
The exposed portion of the charge injection layer is in direct contact with the charge transport layer. Board;
a first electrode positioned on the substrate;
a pixel defining layer having an opening exposing the first electrode and positioned on the substrate;
a surface treatment layer including a first portion on the first electrode and a second portion on the pixel defining layer;
a charge transport layer formed on the surface treatment layer;
a light emitting layer formed on the charge transport layer; and
a second electrode formed on the light emitting layer;
the second portion of the surface treatment layer includes a plurality of grooves that do not overlap the openings of the pixel defining layer;
A portion of the charge transport layer is located inside at least one of the plurality of grooves,
a pinning point is defined between the charge transport layer and the second portion of the surface treatment layer;
an end of the charge transport layer is aligned with the pinning point.

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