Overhanging Patterns for Advanced OLED Patterning

Abstract

The embodiments described herein relate to a device. The device includes a substrate, an overhang structure disposed on the substrate, and a plurality of subpixels. Each overhang structure includes a second structure disposed on a first structure. The second structure has an overhang extension extending laterally past the first structure. The first structure includes a first sidewall opposite a second sidewall. The first and second sidewalls are connected to each other. Each of the plurality of subpixels includes an organic light-emitting diode (OLED) material and a cathode disposed on the OLED material. The cathode extends below the overhang extension such that the cathode contacts the first and second sidewalls of the first structure below the overhang extension.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The embodiments described herein relate generally to displays. More particularly, the embodiments described herein relate to sub-pixel circuits that may be utilized in displays, such as organic light emitting diode (OLED) displays, and methods of forming sub-pixel circuits. [Background technology]

[0002] Input devices, including display devices, may be used in a variety of electronic systems. Organic light-emitting diodes (OLEDs) are light-emitting diodes (LEDs) in which the light-emitting electroluminescent layer is a film of organic compounds that emits light in response to an electric current. OLED devices are classified as bottom-emitting devices if the emitted light passes through a transparent or semi-transparent bottom electrode and substrate on which the panel is fabricated. Top-emitting devices are classified based on whether the light emitted from the OLED device passes through a lid that is added after the device is fabricated. OLEDs are used today to create display devices in many electronic devices. Today's electronics manufacturers are pushing to reduce the size of these display devices while providing higher resolutions than were available just a few years ago.

[0003] Currently, OLED pixel patterning is based on processes that limit panel size, pixel resolution, and substrate size. Photolithography should be used to pattern the pixels, rather than utilizing fine metal masks. Currently, OLED pixel patterning requires the organic material to be stripped after the patterning process. Once stripped, the organic material creates particle problems that impair OLED performance. Therefore, there is a need in the art for sub-pixel circuits and methods of forming sub-pixel circuits that increase the number of pixels per inch and provide improved OLED performance. Summary of the Invention

[0004] In one embodiment, a device is disclosed. The device includes a substrate, an overhang structure disposed on the substrate, and a plurality of subpixels. Each overhang structure includes a second structure disposed on a first structure. The second structure has an overhang extension extending laterally past the first structure. The first structure includes a first sidewall opposite a second sidewall. The first and second sidewalls are connected to each other. Each of the plurality of subpixels includes an organic light-emitting diode (OLED) material and a cathode disposed over the OLED material. The cathode extends below the overhang extension such that the cathode contacts the first and second sidewalls of the first structure below the overhang extension.

[0005] In another embodiment, a device is disclosed. The device includes a substrate, an overhang structure disposed on the substrate, and a plurality of subpixels. Each overhang structure includes a second structure disposed on a first structure. The second structure includes an overhang extension extending laterally past the first structure. The first structure includes a first sidewall opposite the second sidewall and at least four angled sidewalls. At least two of the four angled sidewalls connect a first end of the first sidewall to a first end of the second sidewall. At least two more of the four angled sidewalls connect a second end of the first sidewall to a second end of the second sidewall. The plurality of subpixels includes an organic light-emitting diode (OLED) material and a cathode disposed on the OLED material. The cathode extends below the overhanging extension such that the cathode contacts the first sidewall, the second sidewall, and the at least four angled sidewalls of the first structure below the overhanging extension, and the cathode thickness at a midpoint between the cathode edge and the OLED edge on the first sidewall and the second sidewall is greater than the cathode thickness on the at least four angled sidewalls.

[0006] In yet another embodiment, a method for forming a device is disclosed. The method includes depositing an OLED material at a first angle and depositing a cathode at a second angle so as to contact a first sidewall, a second sidewall, at least two sidewalls, and at least two more sidewalls of a first structure below the overhang extension. Overhangs are disposed on a substrate, and each overhang structure has a second structure disposed above the first structure, the second structure having an overhang extension extending laterally past the first structure. The first structure includes a first sidewall opposite the second sidewall and at least two sidewalls connecting a first end of the first sidewall to a first end of the second sidewall. At least two more sidewalls connect a second end of the first sidewall to a second end of the second sidewall.

[0007] So that the above-listed features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly outlined above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and, therefore, should not be considered as limiting the scope of the present disclosure, which may embrace other embodiments that are equally effective. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a schematic cross-sectional view of a sub-pixel circuit according to an embodiment. [Figure 1B] 1 is a schematic cross-sectional view of an overhang structure of a subpixel circuit, according to an embodiment. [Figure 1C] 1 is a schematic cross-sectional view of a sub-pixel circuit according to an embodiment. [Figure 1D] 1 is a schematic cross-sectional view of an overhang structure of a subpixel circuit, according to an embodiment. [Figure 2] FIG. 2 is a schematic top view of a sub-pixel circuit having a dotted architecture, according to an embodiment. [Figure 3A] FIG. 2 is a cross-sectional view of a subpixel circuit taken along section line AA, according to an embodiment. [Figure 3B] FIG. 10 is a cross-sectional view of a subpixel circuit taken along section line BB, according to an embodiment. [Figure 3C] FIG. 10 is a cross-sectional view of a subpixel circuit at section line CC according to an embodiment. [Figure 3D] FIG. 10 is a cross-sectional view of a subpixel circuit taken along section line DD, according to an embodiment. [Figure 4A] FIG. 2 is a cross-sectional view of a subpixel circuit taken along section line AA, according to an embodiment. [Figure 4B] FIG. 10 is a cross-sectional view of a subpixel circuit taken along section line BB, according to an embodiment. [Figure 4C] FIG. 10 is a cross-sectional view of a subpixel circuit at section line CC according to an embodiment. [Figure 4D] FIG. 10 is a cross-sectional view of a subpixel circuit taken along section line DD, according to an embodiment. [Figure 4E] FIG. 10 is a cross-sectional view of a subpixel circuit taken along section line EE, according to an embodiment. [Figure 5] 1A-1C illustrate a method of forming a sub-pixel circuit, according to an embodiment. [Figure 6A] 1A-1D are schematic cross-sectional views of a substrate during a method for forming a sub-pixel circuit, according to an embodiment. [Figure 6B] 1A-1D are schematic cross-sectional views of a substrate during a method for forming a sub-pixel circuit, according to an embodiment. [Figure 6C] 1A-1D are schematic cross-sectional views of a substrate during a method for forming a sub-pixel circuit, according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] For ease of understanding, the same reference numerals have been used, where possible, to designate identical elements common to the figures, and it is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments unless specifically stated otherwise.

[0010] FIELD OF THE INVENTION The embodiments described herein relate generally to displays. More particularly, the embodiments described herein relate to subpixel circuits and methods of forming subpixel circuits that may be utilized in displays, such as organic light-emitting diode (OLED) displays. In various embodiments, the subpixels use advanced overhang structures to enhance the functionality of the display.

[0011] Each of the embodiments of the subpixel circuits described herein includes a plurality of subpixels, each of which is defined by adjacent overhanging structures present in the subpixel circuit. While the figures show two subpixels, each defined by adjacent overhanging structures, the subpixel circuits of the embodiments described herein include a plurality of subpixels, such as two or more subpixels. Each subpixel has an OLED material configured to emit white, red, green, blue, or other color light when energized. For example, the OLED material of a first subpixel emits red light when energized, the OLED material of a second subpixel emits green light when energized, and the OLED material of a third subpixel emits blue light when energized.

[0012] The overhangs are permanent to the subpixel circuits and include at least a second structure disposed over the first structure. The adjacent overhang structures, which define each subpixel of a display subpixel circuit, define the formation of the subpixel circuits using a deposition technique such as vapor deposition, and define the overhang structures to remain in place after the subpixel circuits are formed. Vapor deposition may be used to deposit the OLED materials (including the hole injection layer (HIL), hole transport layer (HTL), emissive layer (EML), and electron transport layer (ETL)) and the cathode. In one embodiment, the HIL layer has a higher conductivity than the HTL layer. In another embodiment, the HIL layer has a higher energy level than the HTL layer. In some examples, an encapsulation layer may be deposited by vapor deposition. In embodiments including one or more capping layers, the capping layer is disposed between the cathode and the encapsulation layer. The overhang structures and the deposition angle established by the deposition source define shadowing effects during deposition at the deposition angle established by the deposition source. For angled deposition, the deposition source is configured to emit deposition material at a specific angle relative to the overhang structures. An encapsulation layer for each subpixel is disposed over the cathode, and the encapsulation layer extends under at least a portion of each adjacent overhang structure and along a sidewall of each adjacent overhang structure.

[0013] FIG. 1A is a schematic cross-sectional view of a first subpixel circuit 100A according to an embodiment. FIG. 1A corresponds to a cross-section of the first subpixel circuit 100A. FIG. 1B is a schematic cross-sectional view of an overhang structure 110 of the first subpixel circuit 100A according to an embodiment. FIG. 1B is shown in further detail in FIG. 3A. The first subpixel circuit 100A includes a substrate 102. A metal-containing layer 104 may be patterned on the substrate 102, and the metal-containing layer 104 is defined by adjacent pixel-defining layer (PDL) structures 126A disposed on the substrate 102. In one embodiment, the PDL structures 126A are disposed on the substrate 102. In one embodiment, the metal-containing layer 104 is pre-patterned on the substrate 102. For example, the substrate 102 is pre-patterned with a metal-containing layer 104 of indium tin oxide (ITO). The metal-containing layer 104 is configured to act as the anode of each subpixel. In one embodiment, the metal-containing layer 104 is a layer stack of a first transparent conductive oxide (TCO) layer, a second metal-containing layer disposed on the first TCO layer, and a third TCO layer disposed on the second metal-containing layer. The metal-containing layer 104 may include, but is not limited to, chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof, or other suitable conductive materials.

[0014] A plurality of PDL structures 126A are disposed on the substrate 102. The PDL structures 126A include one of an organic material, an organic material having an inorganic coating disposed thereon, or an inorganic material. The organic material of the PDL structures 126A includes, but is not limited to, polyimide. The inorganic material of the PDL structures 126A includes, but is not limited to, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiNO), magnesium fluoride (MgF), or a combination thereof. Adjacent PDL structures 126A define respective subpixels and expose the anode (i.e., the metal-containing layer 104) of each first subpixel circuit 100A.

[0015] The first subpixel circuit 100A includes multiple subpixels 106, including at least a first subpixel 108A and a second subpixel 108B. While the figures show a first subpixel 108A and a second subpixel 108B, the first subpixel circuit 100A of the embodiments described herein may include more than one subpixel 106, such as a third and fourth subpixel. Each subpixel 106 includes an OLED material configured to emit white, red, green, blue, or other color light when energized. For example, the OLED material of the first subpixel 108A may emit red light when energized, the OLED material of the second subpixel 108B may emit green light when energized, the OLED material of the third subpixel may emit blue light when energized, and the OLED material of the fourth subpixel may emit another color light when energized.

[0016] Each subpixel 106 includes an overhang structure 110. The overhang structure 110 is present in the first subpixel circuit 100A. The overhang structure 110 defines each subpixel 106 of the first subpixel circuit 100A. Each overhang structure 110 includes an adjacent overhang 109. The adjacent overhang 109 is defined by an overhang extension 109A of a second structure 110B that extends laterally past the first structure 110A. The second structure 110B is disposed over the first structure 110A. In one embodiment, the second structure 110B is disposed over the first structure 110A.

[0017] In one embodiment, the overhang structure 110 includes a second structure 110B made of a non-conductive inorganic material and a first structure 110A made of a conductive inorganic material. In another embodiment, the overhang structure 110 includes a second structure 110B made of a conductive inorganic material and a first structure 110A made of a conductive inorganic material. The conductive material of the first structure 110A includes aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), copper (Cu), or a combination thereof. The inorganic material of the second structure includes titanium (Ti), silicon nitride (Si3N4), silicon oxide (SiO2), silicon oxynitride (Si2N2O), or a combination thereof. In one embodiment, the first structure is a metal-containing material. In one example, the metal-containing material is a transparent conductive oxide (TCO) material. The TCO material includes, but is not limited to, indium zinc oxide (IZO), indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or a combination thereof. The overhang structure 110 can remain in place. That is, the overhang structure 110 is permanent.

[0018] In one embodiment, an OLED HIL material 150 is disposed on and in contact with the metal-containing layer 104. In one embodiment, the HIL material 150 is different from the material of the first structure 110A and the second structure 110B. An additional OLED material 112 is disposed on the HIL material 150 and extends past the end points of the HIL material 150. In one embodiment, the additional OLED material is disposed on the HIL material 150. In one embodiment, the additional OLED material 112 is different from the material of the first structure 110A and the second structure 110B. The overhang structure 110 and the deposition angle define the OLED end point 158 ​​and the cathode end point 166. The overhang structure 110 defines a shadowing effect during deposition at an angle. The deposition angle is set by the deposition source, which may be an evaporation source. The additional OLED material 112 and the cathode 114 are deposited by evaporation.

[0019] Adjacent overhang 109 is defined by overhanging extension 109A of second structure 110B. To form overhanging extension 109A (shown in FIG. 1B ) of overhang 109, at least bottom surface 107 of second structure 110B is wider than top surface 105 of first structure 110A. Second structure 110B is disposed on top surface 105 of first structure 110A. Overhanging extension 109A of second structure 110B forms overhang 109, allowing second structure 110B to shadow first structure 110A. The shadowing of overhang 109 defines the deposition of each of HIL material 150, additional OLED material 112, and cathode 114. HIL material 150 and additional OLED material 112 are each disposed below overhang 109. Cathode 114 is disposed over the additional OLED material 112 and extends adjacent to and under the overhang 109 .

[0020] In one embodiment, HIL material 150 is disposed over and in contact with metal-containing layer 104 and upper surface 103 of PDL structure 126A. HIL material 150 is disposed under adjacent overhang 109 such that HIL material 150 contacts first structure 110A. Additional OLED material 112 is disposed over HIL material 150. In one embodiment, additional OLED material is disposed over HIL material 150. The additional OLED material extends under adjacent overhang 109 and is disposed over a first portion of first structure 110A.

[0021] The cathode 114 includes a conductive material such as a metal. For example, the cathode 114 includes, but is not limited to, silver, magnesium, chromium, titanium, aluminum, ITO, or a combination thereof. In one embodiment, the material of the cathode 114 is different from the materials of the first structure 110A and the second structure 110B. In some embodiments, the HIL material 150, the additional OLED material 112, and the cathode 114 are disposed on the sidewalls 111 of the first structure 110A.

[0022] Each subpixel 106 includes an encapsulation layer 116. The encapsulation layer 116 may be or may correspond to a local passivation layer. The encapsulation layer 116 of each subpixel is disposed over the cathode 114 (and additional OLED material 112), and the encapsulation layer 116 extends under at least a portion of each of the overhangs 109 and along the sidewalls of each of the first structure 110A and the second structure 110B. The encapsulation layer 116 includes a non-conductive inorganic material, such as a silicon-containing material. The silicon-containing material may include a material containing Si3N4.

[0023] In embodiments including one or more capping layers, the capping layer is disposed between the cathode 114 and the encapsulation layer 116. For example, a first capping layer and a second capping layer are disposed between the cathode 114 and the encapsulation layer 116. Each of the embodiments described herein may include one or more capping layers disposed between the cathode 114 and the encapsulation layer 116. The first capping layer may include an organic material. The second capping layer may include an inorganic material, such as lithium fluoride. The first capping layer and the second capping layer may be deposited by evaporation. In another embodiment, the first subpixel circuit 100A further includes at least one global passivation layer 120 disposed on the overhang structure 110 and the encapsulation layer 116. In yet another embodiment, the subpixels include an intermediate passivation layer disposed over the overhang structure 110 of each of the subpixels 106 and between the encapsulation layer 116 and the global passivation layer 120 .

[0024] FIG. 1C is a schematic cross-sectional view of a second subpixel circuit 100B according to an embodiment. FIG. 1D is a schematic cross-sectional view of a second subpixel circuit 100B according to an embodiment. FIG. 1D is shown in further detail in FIG. 4A. The second subpixel circuit 100B includes a substrate 102. A base layer 121 may be patterned on the substrate 102. The base layer 121 may include, but is not limited to, a CMOS layer. A metal-containing layer 104 (e.g., an anode) may be patterned on the base layer 121, and the metal-containing layer 104 is defined by adjacent pixel separating structures (PIS) 126B disposed on the substrate 102. In one embodiment, the metal-containing layer 104 is pre-patterned on the base layer 121. For example, the base layer 121 may be pre-patterned with a metal-containing layer 104 of indium tin oxide (ITO). The metal-containing layer 104 may be disposed on the substrate 102. The metal-containing layer 104 is configured to act as the anode for each subpixel. In one embodiment, the metal-containing layer 104 is a layer stack of a first transparent conductive oxide (TCO) layer, a second metal-containing layer disposed on the first TCO layer, and a third TCO layer disposed on the second metal-containing layer. The metal-containing layer 104 may include, but is not limited to, chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof, or other suitable conductive materials.

[0025] The PIS 126B is disposed on the substrate 102. The PIS 126B may be disposed on the base layer 121. The PIS 126B includes one of an organic material, an organic material having an inorganic coating disposed thereon, or an inorganic material. The organic material of the PIS 126B includes, but is not limited to, polyimide. The inorganic material of the PIS 126B includes, but is not limited to, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiNO), magnesium fluoride (MgF), or a combination thereof. Adjacent PISs 126B define respective subpixels and expose the metal-containing layer 104 of each second subpixel circuit 100B.

[0026] The second subpixel circuit 100B has multiple subpixel lines (e.g., a first subpixel line 106A and a second subpixel line 106B). The subpixel lines are adjacent to each other along the pixel plane. Each subpixel line includes at least two subpixels. For example, the first subpixel line 106A includes a first subpixel 108A and a second subpixel (not shown), and the second subpixel line 106B includes a third subpixel 108C and a fourth subpixel (not shown). While FIG. 1A shows a first subpixel line 106A and a second subpixel line 106B, the second subpixel circuit 100B of the embodiments described herein may include more than two subpixel lines, such as a third subpixel line and a fourth subpixel line. Each subpixel line includes an OLED material configured to emit white, red, green, blue, or other color light when energized. For example, the OLED material of the first subpixel line 106A emits red light when energized, the OLED material of the second subpixel line 106B emits green light when energized, the OLED material of the third subpixel line emits blue light when energized, and the OLED material of the fourth subpixel emits light of another color when energized. The OLED material within a single pixel line may be configured to emit light of the same color when energized. For example, the OLED material of the first subpixel 108A and the second subpixel of the first subpixel line 106A emits red light when energized, and the OLED material of the third subpixel 108C and the fourth subpixel of the second subpixel line 106B emits green light when energized.

[0027] Each subpixel line includes an adjacent overhang structure 110, and adjacent subpixel lines share adjacent overhang structures 110. The overhang structures 110 are present in the second subpixel circuit 100B. The overhang structures 110 further define each subpixel line of the second subpixel circuit 100B. Each overhang structure 110 includes an adjacent overhang 109. The adjacent overhangs 109 are defined by an overhang extension 109A of the second structure 110B that extends laterally past the top surface 105 of the first structure 110A. The first structure 110A is disposed on the top surface 103 of the PIS 126B. A first endpoint 120A of the bottom surface 118 of the first structure 110A may extend to or past the first edge 117A of the PIS 126B. The second end point 120B of the bottom surface of the first structure 110A may extend to or past the second edge 117B of the PIS 126B. The second structure 110B is disposed on the first structure 110A. The second structure 110B may be disposed on the top surface 105 of the first structure 110A. The second structure 110B may also be disposed on an intermediate structure. The intermediate structure may be disposed on the top surface 105 of the first structure 110A. The intermediate structure may be a seed layer or an adhesion layer. The seed layer functions as a current path for the second subpixel circuit 100B. The seed layer may include a titanium (Ti) material. The adhesion-promoting layer improves adhesion between the first structure 110A and the second structure 110B. The adhesion layer may include a chromium (Cr) material.

[0028] In one embodiment, the overhang structure 110 includes a second structure 110B made of a conductive inorganic material and a first structure 110A made of a non-conductive inorganic material. The conductive material of the second structure 110B includes copper (Cu), chromium (Cr), aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), or a combination thereof. The non-conductive material of the first structure 110A includes amorphous silicon (a-Si), titanium (Ti), silicon nitride (Si3N4), silicon oxide (SiO2), silicon oxynitride (Si2N2O), or a combination thereof. The overhang structure 110 can remain in place; that is, the overhang structure 110 is permanent.

[0029] Adjacent overhangs 109 are defined by overhanging extensions 109A. To form overhanging extensions 109A, at least the bottom surface 107 of second structure 110B is wider than the top surface 105 of first structure 110A. Overhanging extensions 109A of second structure 110B form overhangs 109, allowing second structure 110B to shadow first structure 110A. The shadowing of overhangs 109 defines the deposition of OLED material 112 and cathode 114. OLED material 112 may include one or more of a HIL, a HTL, an EML, and an ETL. OLED material 112 is disposed over and in contact with metal-containing layer 104. OLED material 112 is disposed below adjacent overhangs 109 and may contact sidewalls 111 of first structure 110A. In one embodiment, the OLED material 112 is different from the materials of the first structure 110A, the second structure 110B, and the intermediate structure. The cathode 114 is disposed on the OLED material 112 and extends under the adjacent overhang 109. The cathode 114 extends past the end points of the OLED material 112. The cathode 114 contacts the sidewall 111 of the first structure 110A. The overhang structure 110 and the deposition angle set by the deposition source define the deposition angle. That is, the overhang structure defines the shadowing effect during deposition at the deposition angle set by the deposition source.

[0030] Cathode 114 includes a conductive material such as a metal. For example, cathode 114 includes, but is not limited to, silver, magnesium, chromium, titanium, aluminum, ITO, or a combination thereof. In one embodiment, the material of cathode 114 is different from the materials of first structure 110A, second structure 110B, and intermediate structure. In some embodiments, OLED material 112 and cathode 114 are disposed on sidewall 113 of second structure 110B of overhang structure 110 in the pixel plane, as shown, for example, in FIG. 1C as applied to subpixel circuit 100B. In other embodiments, OLED material 112 and cathode 114 are disposed on top surface 115 of second structure 110B of overhang structure 110 in the pixel plane. In other embodiments, OLED material 112 and cathode 114 terminate on sidewall 111 of first structure 110A. That is, OLED material 112 and cathode 114 are not disposed on sidewalls 113 of second structure 110B or on top surface 115 of second structure 110B in the pixel plane.

[0031] Each subpixel 106 includes an encapsulation layer 116. The encapsulation layer 116 may be or may correspond to a local passivation layer. The encapsulation layer 116 of each subpixel is disposed over the cathode 114 (and OLED material 112), and the encapsulation layer 116 extends along the sidewall 111 of each of the first structure 110A and the second structure 110B, under at least a portion of each overhang 109. The encapsulation layer 116 is disposed over the cathode 114 and extends to contact, in the pixel plane, at least, the cathode 114 over the sidewall 111 of the first structure 110A. In some embodiments, the encapsulation layer 116 extends to contact the sidewall 111 of the first structure 110A. 1C and 1D , encapsulation layer 116 extends to contact second structure 110B at the underside of overhanging extension 109A, the sidewalls 113 of second structure 110B, and the top surface 115 of second structure 110B. In some embodiments, encapsulation layer 116 extends to contact second structure 110B at the underside of overhanging extension 109A, and extends to be disposed over OLED material 112 and cathode 114 when OLED material 112 and cathode 114 are disposed on sidewalls 113 and top surface 115 of second structure 110B. In some embodiments, encapsulation layer 116 terminates at sidewalls 111 of first structure 110A. That is, encapsulation layer 116 is not disposed on sidewall 113 of second structure 110B, top surface 115 of second structure 110B, or the bottom surface of overhang extension 109A of overhang structure 110. Encapsulation layer 116 comprises a non-conductive inorganic material, such as a silicon-containing material. The silicon-containing material may include a material including SiN.

[0032] Each subpixel line may include adjacent isolation structures, and adjacent subpixels in the line plane share adjacent isolation structures. The isolation structures are present in the second subpixel circuit 100B. The isolation structures further define each subpixel in the subpixel line of the second subpixel circuit 100B. The isolation structures are disposed on the top surface 103 of the PIS 126B.

[0033] OLED material 112 is disposed in the line plane over and in contact with metal-containing layer 104 and isolation structures. Cathode 114 is disposed in the line plane over OLED material 112. Encapsulation layer 116 is disposed in the line plane over cathode 114. As shown in FIG. 1D , OLED material 112, cathode 114, and encapsulation layer 116 maintain continuity along the length of the line plane to conduct current across each subpixel 106.

[0034] In embodiments including one or more capping layers, the capping layer is disposed between the cathode 114 and the encapsulation layer 116. For example, a first capping layer and a second capping layer are disposed between the cathode 114 and the encapsulation layer 116. Each of the embodiments described herein may include one or more capping layers disposed between the cathode 114 and the encapsulation layer 116. The first capping layer may include an organic material. The second capping layer may include an inorganic material, such as lithium fluoride. The first and second capping layers may be deposited by evaporation. In another embodiment, the second subpixel circuit 100B further includes at least one global passivation layer disposed over the overhang structure 110 and the encapsulation layer 116. In yet another embodiment, the subpixel includes an intermediate passivation layer disposed over the overhang structure 110 of each subpixel 106 and between the encapsulation layer 116 and the global passivation layer.

[0035] FIG. 2 is a schematic top view of a first subpixel circuit 100A or a second subpixel circuit 100B having a dotted architecture according to an embodiment. FIG. 2 illustrates the first subpixel circuit 100A or the second subpixel circuit 100B before deposition of an encapsulation layer 116. The first subpixel circuit 100A or the second subpixel circuit 100B includes multiple adjacent PDL structures 126A disposed on a substrate 102. An overhang structure 110 is disposed on the top surface 103 of the PDL structures 126A. Each overhang structure 110 has a second structure 110B disposed on the first structure 110A. The first structure 110A includes a first sidewall 275 opposite a second sidewall 276 and at least two sidewalls 271, 272 connecting a first end 275A of the first sidewall 275 to a first end 276A of the second sidewall 276. In one embodiment, the first sidewall 275 and the second sidewall 276 are oriented parallel to the nozzle direction N. The nozzle direction N is orthogonal (e.g., perpendicular) to the scanning direction S. The at least two sidewalls 271, 272 can be oriented at an angle of about 5 degrees to about 85 degrees from the first sidewall 275 and the second sidewall 276. The angle of the at least two sidewalls 271, 272 further defines the OLED end point 158 ​​and the cathode end point 166. The overhang structure 110 and the angle of the at least two sidewalls 271, 272 define a shadowing effect during deposition at an angle. To form the overhang 109, the second structure 110B has an overhang extension 109A that extends laterally past the first sidewall 275, the second sidewall 276, and at least two sidewalls 271, 272 of the first structure 110A.

[0036] First subpixel circuit 100A or second subpixel circuit 100B further includes a plurality of subpixels 106. Each subpixel 106 includes an organic light-emitting diode (OLED) material 112 and a cathode 114 disposed on the additional OLED material 112. Cathode 114 extends below overhang extension 109A and contacts first sidewall 275, second sidewall 276, and at least two sidewalls 271, 272 of first structure 110A below overhang extension 109A. Cathode 114 is disposed on first sidewall 275, second sidewall 276, and at least two sidewalls 271, 272 up to cathode endpoint 166. In some embodiments, the additional OLED material 112 extends below the overhanging extension 109A and contacts the first sidewall 275, the second sidewall 276, and the at least two sidewalls 271, 272 of the first structure 110A below the overhanging extension 109A. The additional OLED material 112 is disposed on the first sidewall 275, the second sidewall 276, and the at least two sidewalls 271, 272 up to the OLED edge point 158.

[0037] In one embodiment, the subpixel further includes a metal-containing layer 104 and a via hole 290. In one embodiment, the via hole is disposed through the metal-containing layer 104. A conductive layer is disposed within the via hole 290 to connect the metal-containing layer 104 to a thin film transistor (TFT) disposed below the metal-containing layer 104. The TFT provides drive current to the plurality of subpixels 106. The metal-containing layer 104 may be patterned on the substrate 102 and is defined by adjacent pixel-defining layer (PDL) structures 126A disposed on the substrate 102 of the first subpixel circuit 100A. In one embodiment, the metal-containing layer 104 is pre-patterned on the substrate 102. For example, the substrate 102 is pre-patterned with an indium tin oxide (ITO) metal-containing layer 104. The metal-containing layer 104 is configured to act as the anode of each subpixel.

[0038] In one embodiment, the subpixel 106 further includes at least two more sidewalls 273, 274 connecting the second end 275B of the first sidewall 275 to the second end 276B of the second sidewall 276. The at least two more sidewalls 273, 274 can be disposed at an angle between about 5 degrees and about 85 degrees from the first sidewall 275 and the second sidewall 276. The angles of the at least two more sidewalls 273, 274 further define the OLED edge 158 and the cathode edge 166. The overhang structure 110 and the angles of the at least two more sidewalls 273, 274 define a shadowing effect during deposition at an angle. At least two sidewalls 271, 272 include a first portion 271 and a second portion 272, and at least two more sidewalls include a third portion 273 and a fourth portion 274. The first portions 271 of the at least two side walls 271, 272 are opposite the fourth portions 274 of the at least two more side walls 273, 274. The second portions 272 of the at least two side walls 271, 272 are opposite the third portions 273 of the at least two more side walls 273, 274. In one embodiment, the first portions 271 of the at least two side walls 271, 272 are opposite the fourth portions 274 of the at least two more side walls 273, 274 and parallel to the fourth portions 274 of the at least two more side walls 273, 274, and the second portions 272 of the at least two side walls 271, 272 are opposite the third portions 273 of the at least two more side walls 273, 274 and parallel to the third portions 273 of the at least two more side walls 273, 274.

[0039] Cathode 114 extends under overhanging extension 109A and contacts first sidewall 275, second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 of first structure 110A under overhanging extension 109A. Cathode 114 is disposed on first sidewall 275, second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 to cathode endpoint 166. In some embodiments, additional OLED material 112 extends under overhanging extension 109A and contacts first sidewall 275, second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 of first structure 110A under overhanging extension 109A. Additional OLED material 112 is disposed on a first sidewall 275 , a second sidewall 276 , at least two sidewalls 271 , 272 , and at least two more sidewalls 273 , 274 up to OLED edge point 158 ​​.

[0040] In one embodiment, a first sidewall 275, a second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 form a hexagonal subpixel 106. A first end 275A of the first sidewall 275 connects to first portions 271 of the at least two sidewalls 271, 272, and a second end 275B of the first sidewall 275 connects to third portions 273 of the at least two more sidewalls 273, 274. A first end 276A of the second sidewall 276 connects to second portions 272 of the at least two sidewalls 271, 272, and a second end 276B of the second sidewall 276 connects to fourth portions 274 of the at least two more sidewalls 273, 274. The first portion 271 connects to the second portion 272. The third portion 273 connects to the fourth portion 274. In some embodiments, the corner formed by the first sidewall 275, the second sidewall 276, the at least two sidewalls 271, 272, and the at least two more sidewalls 273, 274 has a corner radius.

[0041] 3A-3D show cross-sectional views of a subpixel 106. FIG. 3A is a cross-sectional view of a first sidewall 275 of a first subpixel circuit 100A taken along cross-sectional line AA. FIG. 3B is a cross-sectional view of a second sidewall 275 of a first subpixel circuit 100A taken along cross-sectional line BB. FIG. 3C is a cross-sectional view of a first portion 271 of at least two sidewalls 271, 272 of a first subpixel circuit 100A taken along cross-sectional line CC. FIG. 3D is a cross-sectional view of a second portion 272 of at least two sidewalls 271, 272 of a first subpixel circuit 100A taken along cross-sectional line DD. FIGS. 3A-3D show the cross-section after deposition of a cathode 114, additional OLED material 112, and HIL material 150. The first sidewall 275 of the first structure 110A and the second sidewall 276 of the first structure 110A have a cathode thickness t1. Cathode thickness t1 is the thickness of a first sidewall 275 of first structure 110A and a second sidewall 276 of first structure 110A at the midpoint between cathode edge 166 and OLED edge 158. First cathode volume v1 is the total volume of cathode 114 disposed on first sidewall 275 and second sidewall 276 from cathode edge 166 to OLED edge 158. At least two sidewalls 271, 272 of first structure 110A and at least two more sidewalls 273, 274 of first structure 110A have cathode thickness t2. Cathode thickness t2 is the thickness of at least two sidewalls 271, 272 and at least two more sidewalls 273, 274 at the midpoint between cathode edge 166 and OLED edge 158. The second cathode volume v2 is the total volume from the cathode end point 166 to the OLED end point 158 ​​of the cathode 114 disposed on at least two sidewalls 271, 272 and at least two more sidewalls 273, 274. In one embodiment, the cathode thickness t1 is greater than the cathode thickness t2. In one embodiment, the cathode thickness t2 is about 10% to about 99% of the cathode thickness t1. In one embodiment, the first cathode volume v1 of the cathode 114 on the first sidewall 275 and the second sidewall 276 is greater than the second cathode volume v2 on the at least two sidewalls 271, 272 and at least two more sidewalls 273, 274.The second cathode volume v2 on the at least two sidewalls 271, 272 and the at least two other sidewalls 273, 274 is between about 10% and about 99% of the first cathode volume v1 of the cathode 114 on the first sidewall 275 and the second sidewall 276. The first sidewall 275 and the second sidewall 276 have an OLED thickness t3. The at least two sidewalls 271, 272 and the at least two other sidewalls 273, 274 have an OLED thickness t4. The OLED thicknesses t3 and t4 are measured at the OLED edge points 158.

[0042] The overhang structure 110 defines a first sidewall 275 and a second sidewall 276 and cathode termination points 166 for at least two sidewalls 271, 272 and at least two more sidewalls 273, 274. The cathode termination points 166 ensure that the cathode 114 contacts the first structure 110A of the overhang structure 110, which is conductive to complete the subpixel circuit 100. The cathode termination points 166 on the sidewalls 271, 272, 273, 274, 275, and 276 prevent the PDL structure 126A from contacting the etchant in subsequent processing. The overhang structure 110 defines an OLED termination point 158 ​​for the first sidewall 275 and a second sidewall 276 and at least two sidewalls 271, 272 and at least two more sidewalls 273, 274. In some embodiments, the OLED edge 158 has edges along a first sidewall 275, a second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 such that the OLED material 112 does not contact the second structure 110B.

[0043] 4A-4E show cross-sectional views of a subpixel 106. FIG. 4A is a cross-sectional view of a first sidewall 275 of a second subpixel circuit 100B along cross-section line AA. FIG. 4B is a cross-sectional view of a second sidewall 276 of a second subpixel circuit 100B along cross-section line BB. FIG. 4C is a cross-sectional view of a first portion 271 of at least two sidewalls 271, 272 of a second subpixel circuit 100B along cross-section line CC. FIG. 4D is a cross-sectional view of a second portion 272 of at least two sidewalls 271, 272 of a second subpixel circuit 100B along cross-section line DD. FIG. 4E is a cross-sectional view of a second portion 272 of at least two sidewalls 271, 272 of a second subpixel circuit 100B along cross-section line EE. FIGS. 4A-4E show the cross-section after deposition of a cathode 114, additional OLED material 112, and HIL material 150. A first sidewall 275 of the first structure 110A and a second sidewall 276 of the first structure 110A have a cathode thickness t5. The cathode thickness t5 is the thickness of the first sidewall 275 of the first structure 110A and the second sidewall 276 of the first structure 110A at the midpoint between the cathode end point 166 and the OLED end point 158. A first cathode volume v1 is the total volume of the cathode 114 disposed on the first sidewall 275 and the second sidewall 276 from the cathode end point 166 to the OLED end point 158. At least two sidewalls 271, 272 of the first structure 110A and at least two more sidewalls 273, 274 of the first structure 110A have a cathode thickness t6. Cathode thickness t6 is the thickness of at least two sidewalls 271, 272 and at least two more sidewalls 273, 274 at the midpoint between cathode end point 166 and OLED end point 158. Second cathode volume v2 is the total volume of cathode 114 disposed on at least two sidewalls 271, 272 and at least two more sidewalls 273, 274 from cathode end point 166 to OLED end point 158. In one embodiment, cathode thickness t5 is greater than cathode thickness t6. In one embodiment, cathode thickness t6 is about 10% to about 99% of cathode thickness t5.In one embodiment, a first cathode volume v1 of the cathode 114 on the first sidewall 275 and the second sidewall 276 is larger than a second cathode volume v2 on the at least two sidewalls 271, 272 and at least two more sidewalls 273, 274. The second cathode volume v2 on the at least two sidewalls 271, 272 and at least two more sidewalls 273, 274 is between about 10% and about 99% of the first cathode volume v1 of the cathode 114 on the first sidewall 275 and the second sidewall 276. The first sidewall 275 and the second sidewall 276 have an OLED thickness t7. The at least two sidewalls 271, 272 and at least two more sidewalls 273, 274 have an OLED thickness t8. The OLED thicknesses t7 and t8 are measured at the OLED edge points 158.

[0044] The overhang structure 110 defines a first sidewall 275 and a second sidewall 276 and cathode termination points 166 for at least two sidewalls 271, 272 and at least two more sidewalls 273, 274. The cathode termination points 166 ensure that the cathode 114 contacts the first structure 110A of the overhang structure 110, which is conductive to complete the subpixel circuit 100. The cathode termination points 166 on the sidewalls 271, 272, 273, 274, 275, and 276 prevent the PDL structure 126A from contacting the etchant in subsequent processing. The overhang structure 110 defines an OLED termination point 158 ​​for the first sidewall 275 and a second sidewall 276 and at least two sidewalls 271, 272 and at least two more sidewalls 273, 274. In some embodiments, OLED edge 158 has edges along first sidewall 275, second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 such that OLED material 112 does not contact second structure 110B. As shown in FIG. 4E , the angles of at least two sidewalls 271, 272 and the angles of at least two more sidewalls 273, 274 further define OLED edge 158 and cathode edge 166. Overhang structure 110 and the angles of at least two sidewalls 271, 272 and at least two more sidewalls 273, 274 define a shadowing effect during deposition at an angle.

[0045] FIG. 5 illustrates a method 500 for forming the subpixel circuit 100. FIGS. 6A-6C are schematic cross-sectional views of the substrate 102 during the method 500 for forming the subpixel circuit 100. In operation 501, additional OLED material 112 is deposited on the first sidewall 275 at a first angle, as shown in FIGS. 6A and 6B. In one embodiment, the deposition is evaporation. In one embodiment, the deposition of the additional OLED material 112 is performed as the substrate 102 advances in a scanning direction S. In another embodiment, the deposition of the additional OLED material 112 is performed as a deposition source advances in the scanning direction S. The deposition source includes multiple nozzles extending along a nozzle direction N. As the nozzle moves along the scanning direction S, the overhanging structure 110 ensures that the height of the OLED edge 158 on the first sidewall 275 does not contact the second structure 110B. Shadowing of the overhanging extension 109 of the second structure defines the deposition of the additional OLED material 112 at an angle set by the evaporation source. That is, the overhang structure 110 defines a shadowing effect during deposition at a deposition angle set by a deposition source configured to emit OLED material at a particular angle relative to the overhang structure 110. The first sidewall 275 is orthogonal (e.g., perpendicular) to the scanning direction S.

[0046] In operation 502, additional OLED material 112 is deposited on at least two sidewalls 271, 272 at a second angle. In some embodiments, additional OLED material 112 is deposited on at least two more sidewalls 273, 274. The at least two or more sidewalls 273, 274 are at an angle of about 5 degrees to about 85 degrees from the first sidewall 275 and the second sidewall 276. The angle of the at least two or more sidewalls 273, 274 relative to the first sidewall 275 and the second sidewall 276 affects the deposition angle as the nozzle moves along the scanning direction S. As the nozzle moves along the scanning direction S, the overhanging structure 110 ensures that the height of the OLED edge 158 on the at least two sidewalls 271, 272 does not contact the second structure 110B.

[0047] In operation 503, additional OLED material 112 is deposited at a first angle onto second sidewall 276. As the nozzle moves along scanning direction S, overhang structure 110 ensures that the height of OLED edge 158 on second sidewall 276 does not contact second structure 110B. Second sidewall 276 is orthogonal (e.g., perpendicular) to scanning direction S.

[0048] In operation 504, cathode 114 is deposited on first sidewall 275 at a third angle. In one embodiment, the deposition is vapor deposition. Shadowing of overhang extension 109 of the second structure defines the deposition of cathode 114 at an angle set by the deposition source. That is, overhang structure 110 defines a shadowing effect during deposition at a deposition angle set by the deposition source configured to emit cathode 114 at a specific angle relative to overhang structure 110.

[0049] In operation 505, a cathode is deposited on at least two sidewalls 271, 272 at a second angle. In some embodiments, a cathode 114 is deposited on at least two more sidewalls 273, 274. The at least two or more sidewalls 273, 274 are at an angle of about 5 degrees to about 85 degrees from the first sidewall 275 and the second sidewall 276. The angle of the at least two or more sidewalls 273, 274 relative to the first sidewall 275 and the second sidewall 276 affects the deposition angle as the nozzle moves along the scan direction S.

[0050] In operation 506, cathode 114 is deposited on second sidewall 276 at a third angle.

[0051] In the embodiment of Figures 3A-3D, the cathode 114 is deposited such that the cathode thickness on the first sidewall 275 and the second sidewall 276 is thickness t1, as shown in Figures 3A and 3B. The cathode 114 is deposited such that the cathode thickness on the first portion 271 of at least two sidewalls 271, 272 and the third portion 273 of at least two more sidewalls 273, 274 is thickness t2, as shown in Figure 3C. The cathode thickness t1 on the first sidewall 275 and the second sidewall 276 is greater than the cathode thickness t2 on the first portion 271 and the third portion 274. The cathode 114 is deposited such that the cathode thickness on the second portion 272 of at least two sidewalls 271, 272 and the fourth portion 274 of at least two more sidewalls 273, 274 is thickness t2, as shown in Figure 3D. The cathode thickness t1 of the first sidewall 275 and the second sidewall 276 is greater than the cathode thickness t2 on the second portion 272 and the fourth portion 274. In one embodiment, the ratio of the thickness t1 of the first sidewall 275 and the second sidewall 276 to the thickness t2 of the at least two sidewalls 271, 272 and the at least two more sidewalls 273, 274 is between about 1:1 and about 10:1.

[0052] In the embodiment of Figures 4A-4D, the cathode 114 is deposited such that the cathode thickness on the first sidewall 275 is thickness t5, as shown in Figures 4A and 4B. The cathode 114 is deposited such that the cathode thickness on the first portion 271 of at least two sidewalls 271, 272 and the third portion 273 of at least two more sidewalls 273, 274 is thickness t6, as shown in Figure 3C. The cathode thickness t5 on the first sidewall 275 and the second sidewall 276 is greater than the cathode thickness t6 on the first portion 271 and the third portion 274. The cathode 114 is deposited such that the cathode thickness on the second portion 272 of at least two sidewalls 271, 272 and the fourth portion 274 of at least two more sidewalls 273, 274 is thickness t6, as shown in Figure 3D. The cathode thickness t5 of the first sidewall 275 and the second sidewall 276 is greater than the cathode thickness t6 on the second portion 272 and the fourth portion 274. In one embodiment, the ratio of the thickness t5 of the first sidewall 275 and the second sidewall 276 to the thickness t6 of the at least two sidewalls 271, 272 and the at least two more sidewalls 273, 274 is between about 1:1 and about 10:1.

[0053] In one embodiment, deposition of the cathode 114 is performed as the substrate 102 advances in the scanning direction S. In another embodiment, deposition of the cathode 114 is performed as a deposition source advances in the scanning direction S. The thickness of the cathode is a result of the deposition angle and the configuration of the overhang 109. The deposition source includes multiple nozzles extending along a nozzle direction N. As the nozzle moves along the scanning direction, the overhang structure 110 ensures that the cathode 114 on the first sidewall 275, the second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 contact the first structure 110A to complete the subpixel circuit 100. The cathode 114 prevents the PDL structure 126A from contacting the etchant in subsequent processes. In one embodiment, the overhang structure 110 ensures that the cathode termination points 166 on the first sidewall 275, the second sidewall 276, at least two sidewalls 271, 272, and at least two more sidewalls 273, 274 contact the overhang 109 to form a circuit between the metal-containing layer 104, the OLED material 112, and the cathode.

[0054] In summary, each of the embodiments of the subpixel circuit described herein includes a plurality of subpixels, each of the subpixels defined by adjacent overhang structures present in the subpixel circuit. The overhangs define a cathode thickness for a first sidewall, a second sidewall, and at least two sidewalls connecting the first sidewall and the second sidewall. The cathode thickness on the first sidewall and the second sidewall is greater than the cathode thickness on at least two sidewalls.

[0055] While the foregoing is directed to embodiments of the present disclosure, other and additional embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

Claims

1. A substrate; overhanging structures disposed above the substrate, each overhanging structure having a second structure disposed above a first structure, the second structure having an overhanging extension extending laterally past the first structure, the first structure comprising: a first sidewall opposite a second sidewall, the first sidewall and the second sidewall being connected to each other; an overhang structure comprising: a plurality of sub-pixels, each sub-pixel being: an organic light emitting diode (OLED) material; a cathode disposed over the OLED material, the cathode extending beneath the overhanging extension such that the cathode contacts the first sidewall and the second sidewall of the first structure beneath the overhanging extension; a plurality of sub-pixels, each of which comprises: A device comprising:

2. at least two side walls connecting a first end of the first side wall to the first end of the second side wall; at least two more side walls connecting the second ends of the first side walls to the second ends of the second side walls; The device of claim 1 further comprising:

3. 3. The device of claim 2, wherein a cathode thickness on the first sidewall and the second sidewall at a midpoint between the cathode end and the OLED end is greater than the cathode thickness on the at least two sidewalls.

4. 4. The device of claim 3, wherein a ratio of a thickness of the cathode thickness on the first sidewall and the second sidewall to a thickness of the cathode thickness on the at least two sidewalls is between 1:1 and 10:

1.

5. The device of claim 1 , wherein the plurality of subpixels are hexagonal subpixels.

6. The device of claim 1 , wherein each subpixel further comprises a via hole disposed therethrough.

7. The device of claim 1 , further comprising a pixel definition layer (PDL) structure disposed on the substrate, the overhang structure being disposed above the PDL structure.

8. The PDL structure is made of polyimide, silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (Si 2 N 2 O), magnesium fluoride (MgF 2 8. The device of claim 7, comprising:

9. The device of claim 1 , further comprising a pixel separating structure (PIS) disposed on the substrate, the overhang structure being disposed above the PIS.

10. The PIS is a mixture of polyimide, silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (Si 2 N 2 O), magnesium fluoride (MgF 2 10. The device of claim 9, comprising:

11. A substrate; overhanging structures disposed above the substrate, each overhanging structure having a second structure disposed above a first structure, the second structure having an overhanging extension extending laterally past the first structure, the first structure comprising: a first sidewall opposite a second sidewall and at least four angled sidewalls, at least two of the four angled sidewalls connecting a first end of the first sidewall to the first end of the second sidewall, and at least two more of the four angled sidewalls connecting a second end of the first sidewall to a second end of the second sidewall; an overhang structure comprising: a plurality of sub-pixels, each sub-pixel being: an organic light emitting diode (OLED) material; a cathode disposed over the OLED material, the cathode extending below the overhanging extension such that the cathode contacts the first sidewall, the second sidewall, and the at least four angled sidewalls of the first structure below the overhanging extension, the cathode having a thickness at a midpoint between a cathode edge and an OLED edge on the first sidewall and the second sidewall that is greater than the cathode thickness on the at least four angled sidewalls; a plurality of sub-pixels, each of which comprises: A device comprising:

12. 12. The device of claim 11, further comprising a pixel defining layer (PDL) structure disposed on the substrate, the overhang structure being disposed above the PDL structure.

13. The device of claim 11 , wherein the plurality of subpixels are hexagonal subpixels, and the first sidewall and the second sidewall are perpendicular to a scanning direction.

14. The device of claim 11 , further comprising a pixel separating structure (PIS) disposed on the substrate, the overhang structure being disposed above the PIS.

15. a ratio of the thickness of the cathode thickness on the first sidewall and the second sidewall to the thickness of the cathode thickness on the at least four angled sidewalls is between 1:1 and 10:1; The device of claim 11.

16. 1. A method of forming a device, comprising: depositing OLED material at a first angle; An overhang is disposed on the substrate, each overhang structure having a second structure disposed on a first structure, the second structure having an overhang extension extending laterally past the first structure, the first structure comprising: a first sidewall opposite a second sidewall, and at least two sidewalls connecting a first end of the first sidewall to a first end of the second sidewall; at least two more side walls connecting the second ends of the first side walls to the second ends of the second side walls; depositing the depositing the cathode at a second angle such that the cathode contacts the first sidewall, the second sidewall, the at least two sidewalls, and the at least two more sidewalls of the first structure under the overhanging extension; A method comprising:

17. 17. The method of claim 16, wherein the OLED material and the cathode are deposited as the substrate or deposition source moves in a scanning direction.

18. a cathode thickness at a midpoint between a cathode edge and an OLED edge on the first sidewall and the second sidewall is greater than the cathode thickness on the at least two sidewalls; 17. The method of claim 16.

19. a ratio of the thickness of the cathode thickness on the first sidewall and the second sidewall to the thickness of the cathode thickness on the at least two sidewalls is between 1:1 and 10:1; 17. The method of claim 16.

20. Each subpixel is an anode; a via hole disposed through the anode; 17. The method of claim 16, further comprising:

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