Strangler film for OLED structures

Abstract

Embodiments described herein relate generally to a display. More specifically, embodiments described herein relate to sub-pixel circuits and methods of forming sub-pixel circuits that can be used in displays such as organic light emitting diode (OLED) displays. In one or more embodiments, a sub-pixel includes adjacent overhang structures disposed above a substrate. Each overhang structure has an overhang extension that extends laterally over a sidewall of each overhang structure. The sub-pixel further includes a pixel isolation structure (PIS) disposed above the substrate between the adjacent overhang structures. The PIS includes an upper surface and at least two sidewalls opposite each other. An anode is disposed above the PIS. An OLED material is disposed above the anode and extends over the upper surface and the sidewalls of the PIS. The OLED material further extends under the overhang extension. A cathode is disposed above the OLED material.

Description

Technical Field

[0001] The embodiments described herein generally relate to a display. More specifically, the embodiments described herein relate to subpixel circuitry that can be used in displays such as organic light-emitting diode (OLED) displays and methods for forming subpixel circuitry. Background Technology

[0002] Input devices, including display devices, can be used in a wide variety of electronic systems. Organic light-emitting diodes (OLEDs) are light-emitting diodes (LEDs) in which the 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 translucent bottom electrode and substrate on which the panel is manufactured. Top-emitting devices are classified based on whether the light emitted from the OLED device passes through a cover added after the device is manufactured. Today, OLEDs are used to form display devices in many electronic products. Large glass OLED devices can be made for TV applications. However, these large glass OLED devices can be expensive to produce, largely because a local cathode contact needs to be formed for each sub-pixel.

[0003] Therefore, what is needed in the art is a subpixel circuit with an integral cathode contact to reduce manufacturing costs, and a method for forming the subpixel circuit. Summary of the Invention

[0004] The embodiments described herein generally relate to a display. More specifically, the embodiments described herein relate to subpixel circuitry that can be used in displays such as organic light-emitting diode (OLED) displays and methods for forming subpixel circuitry.

[0005] In one or more embodiments, a sub-pixel includes adjacent overhang structures disposed above a substrate. Each overhang structure has an overhang extension extending laterally through a sidewall of each overhang structure. The sub-pixel further includes a pixel isolation structure (PIS) disposed above the substrate between adjacent overhang structures. The PIS includes a top surface and at least two sidewalls opposite each other. An anode is disposed on the PIS. OLED material is disposed above the anode and extends above the top surface and sidewalls of the PIS. The OLED material further extends below the overhang extensions. The OLED material includes a choke portion having one or more layers. At least one of the one or more layers includes: a continuous region disposed above the anode and the top surface of the PIS; and a choke region disposed above the sidewalls and extending below the overhang extensions. The choke region and the continuous region of the at least one layer are electrically separated from each other. The OLED material further includes a continuous portion disposed above the choke portion. A cathode is disposed above the OLED material.

[0006] In one or more embodiments, a sub-pixel includes adjacent overhang structures disposed on a substrate along a line plane. The adjacent overhang structures include: a first structure disposed above the substrate; and a second structure disposed on the first structure. The bottom surface of the second structure extends laterally through the upper surface of the first structure, thereby defining an overhang extension. A pixel isolation structure (PIS) is disposed on the substrate and extends along a line plane between the adjacent overhang structures. The PIS includes an upper surface and a plurality of sidewalls. An anode is disposed on the PIS. OLED material is disposed above the anode and extends above the upper surface of the PIS and the plurality of sidewalls. The OLED material further extends below the overhang extension. The OLED material includes a choke portion. The choke portion includes: a continuous region disposed above the anode and the upper surface of the PIS; and a choke region disposed above the plurality of sidewalls and extending below the overhang extension. The choke region and the continuous region are electrically separated from each other. The OLED material further includes a continuous portion disposed above the choke portion. The cathode is placed above the OLED material.

[0007] In one or more embodiments, a device includes a plurality of subpixel lines. Each subpixel line includes at least one subpixel. Each subpixel includes an adjacent overhang structure disposed on a substrate along a line plane. The adjacent overhang structure includes: a first structure disposed on the substrate; and a second structure disposed on the first structure. The bottom surface of the second structure extends laterally through the upper surface of the first structure to define an overhang extension. A pixel isolation structure (PIS) is disposed on the substrate and extends along a line plane between adjacent overhang structures. The PIS includes an upper surface and a plurality of sidewalls. An anode is disposed on the PIS. OLED material is disposed above the anode and extends above the upper surface of the PIS and the plurality of sidewalls. The OLED material further extends below the overhang extension. The OLED material includes a choke portion. The choke portion includes: a continuous region disposed above the anode and the upper surface of the PIS; and a choke region disposed above the plurality of sidewalls and extending below the overhang extension. The choke region and the continuous region are electrically separated from each other. The OLED material further includes a continuous portion disposed above the choke portion. A cathode is disposed above the OLED material. An encapsulation layer is disposed above the cathode. Attached Figure Description

[0008] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly outlined above, can be obtained with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate exemplary embodiments only and are therefore not intended to limit the scope of the embodiments, and other equally effective embodiments are appreciated.

[0009] Figure 1A This is a schematic cross-sectional view of the sub-pixel circuit according to an embodiment.

[0010] Figure 1B This is a schematic cross-sectional view of the sub-pixel circuit according to an embodiment.

[0011] Figure 1C This is a schematic top view of the sub-pixel circuit according to an embodiment.

[0012] Figure 2A This is a schematic cross-sectional view of a portion of a sub-pixel circuit having a single stacked structure according to an embodiment.

[0013] Figure 2B This is a schematic cross-sectional view of a sub-pixel circuit with a series stacked structure according to an embodiment.

[0014] Figure 3 This is a flowchart of a method for forming a sub-pixel circuit according to an embodiment.

[0015] Figures 4A to 4D This is a schematic cross-sectional view of a substrate during a method for forming a sub-pixel circuit according to an embodiment.

[0016] To facilitate understanding, the same element symbols have been used where possible to denote common elements across the figures. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. Detailed Implementation

[0017] The embodiments described herein generally relate to a display. More specifically, the embodiments described herein relate to subpixel circuitry that can be used in displays such as organic light-emitting diode (OLED) displays and methods for forming subpixel circuitry.

[0018] In one embodiment, a sub-pixel is provided. The sub-pixel includes an anode, a cantilever structure, an organic light-emitting diode (OLED) material, and a cathode. The anode is disposed on the upper surface of a pixel isolation structure (PIS). The cantilever structure is disposed between adjacent PISs. The cantilever structure includes a second structure disposed above the first structure. The bottom surface of the second structure extends laterally through the upper surface of the first structure. The cantilever is defined by a cantilever extension of the second structure extending laterally through the upper surface of the first structure. The first structure is disposed above a substrate. The OLED material is disposed above the anode, the upper surface of the PIS, and above the substrate below the cantilever of the cantilever structure. The cathode is disposed above the OLED material and the upper surface of the PIS.

[0019] Each of the subpixel circuits described herein includes a plurality of subpixels, each of which is defined by an adjacent overhang structure that is permanent for the subpixel circuit. Although the figures depict two subpixels, each defined by an adjacent overhang structure, the subpixel circuits of the embodiments described herein include a plurality of subpixels, such as two or more. Each subpixel has an OLED material configured to emit white, red, green, blue, or other colored light when powered. For example, the OLED material of a first subpixel emits red light when powered, the OLED material of a second subpixel emits green light when powered, and the OLED material of a third subpixel emits blue light when powered.

[0020] Figure 1A This is a schematic cross-sectional view of the sub-pixel circuit 100. Figure 1A The cross-sectional view is along Figure 1C It is intercepted by the cross-sectional line 1A-1A (e.g., the pixel plane). Figure 1B This is a schematic cross-sectional view of the sub-pixel circuit 100. Figure 1B The cross-sectional view is along Figure 1CThe sub-pixel circuit 100 is cut along a cross-sectional line 1B-1B (e.g., a line plane). The sub-pixel circuit 100 includes a substrate 102. The substrate 102 is a backplane. The backplane includes, but is not limited to, a complementary metal-oxide-semiconductor (CMOS) array or a thin-film transistor (TFT) array. Pixel isolation structures (PIS) 120 may be patterned on the substrate 102. The PIS 120 extends along the line plane. In one embodiment, the PIS 120 is pre-patterned on a substrate layer. Each PIS 120 includes at least two sidewalls 123 opposite to each other. The PIS 120 has a height H1. The height H1 is defined by the distance between the lower surface 121 and the upper surface 122 of the PIS 120. The height H1 is approximately 200 nm to approximately 300 nm. PIS 120 is formed from materials including metals (such as silver (Ag), indium tin oxide (ITO), aluminum polymer composite (APC), aluminum copper alloy (AlCu), titanium nitride (TiN), tin oxide (SnO2), indium gallium zinc oxide (IGZO), or any combination thereof). The materials of PIS 120 also include metallic materials (such as silicon nitride (SiN)). x One or more insulating layers are formed between a PIS 120 and silicon dioxide (SiO2) or a combination thereof. Each PIS 120 is separated from each other by a distance D2 in the pixel plane. The distance D2 is about 15µm to about 30µm. An anode 104 is deposited on the upper surface 122 of each PIS 120. The anode 104 is configured to operate as the anode of the corresponding sub-pixel. The distance D1 is defined by the distance between the outer edge of the anode and the sidewall 123 of the PIS 120. The distance D1 is about 1µm to about 2µm. In one embodiment, the anode 104 is a stack of layers consisting 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 anode 104 includes, but is not limited to, chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof, or other suitable conductive materials.

[0021] The anode 104 has a width W1 and a length L1. The width W1 of the anode 104 is defined by the distance the anode 104 extends across the PIS120 in the pixel plane, such as... Figure 1A As shown. The width W1 of the anode 104 is approximately 10µm to approximately 20µm. The length L1 of the anode 104 is defined by the distance the anode 104 extends across PIS 120 in the line plane, as shown. Figure 1B As shown. The length L1 of the anode 104 is approximately 110µm to approximately 225µm.

[0022] PIS 120 includes an opening 125. The opening 125 extends from the upper surface 122 to the lower surface 121. An anode 104 is deposited within the opening 125. A portion of the anode 104 contacts the substrate 102 within the opening 125. This portion of the anode 104 within the opening 125 electrically connects the anode 104 to the substrate 102, such that the anode 104 can conduct current flowing through the substrate 102.

[0023] The subpixel circuit 100 has a plurality of subpixel lines (e.g., a first subpixel line 106A and a second subpixel line 106B along the Y direction). The subpixel lines are adjacent to each other along the pixel plane. Each subpixel line includes at least one subpixel. For example, the first subpixel line 106A includes a first subpixel 108A, and the second subpixel line 106B includes a second subpixel 108B. Although Figure 1A The first sub-pixel line 106A and the second sub-pixel line 106B are depicted, but the sub-pixel circuit 100 of the embodiments described herein may include two or more sub-pixel lines, such as a third sub-pixel line 106C (e.g., Figure 1C (as shown) and a fourth sub-pixel. Each sub-pixel line has an OLED material configured to emit white, red, green, blue, or other colored light when powered on. For example, the OLED material of the first sub-pixel line 106A emits red light when powered on, the OLED material of the second sub-pixel line 106B emits green light when powered on, the OLED material of the third sub-pixel line 106C emits blue light when powered on, and the OLED material of the fourth sub-pixel emits another color of light when powered on.

[0024] Each subpixel line includes an adjacent overhang structure 110, wherein adjacent subpixel lines share the adjacent overhang structure 110 in the pixel plane. The overhang structure 110 is permanent for the subpixel circuit 100. The overhang structure 110 further defines each subpixel line of the subpixel circuit 100. Each overhang structure 110 includes an adjacent overhang portion 109. The adjacent overhang portion 109 is defined by an overhang extension 109A of a second structure 110B extending laterally through the upper surface 105 of the first structure 110A. The first structure 110A is disposed above the substrate 102. The first structure 110A is formed of a conductive material. The conductive material includes metallic materials, such as titanium (Ti), aluminum (Al), magnesium (Mg), or any other metal that can be patterned. The first structure serves as an integral cathode contact of the subpixel circuit 100. The second structure is formed of a resistive material, such as polyimide (PI) or silicon dioxide (SiO2) . The overhang structure 110 is able to remain in place, i.e., it is permanent.

[0025] Adjacent overhangs 109 are defined by overhang extensions 109A. At least the bottom surface 107 of the second structure 110B is wider than the upper surface 105 of the first structure 110A to form overhang extensions 109A. The overhang extensions 109A of adjacent second structures 110B form adjacent overhangs 109 and allow the second structure 110B to shield the first structure 110A. The shielding of adjacent overhangs 109 provides for the vapor deposition of OLED material 112 and cathode 115. OLED material 112 and cathode 115 extend across each sub-pixel line in the line plane, as... Figure 1B As shown. OLED material 112 includes a choked portion 113 and a continuous portion 114. OLED material 112 may include a single stacked structure or a series stacked structure. A single stacked structure in Figure 2A This is shown in more detail below. The cascaded stacked structure is... Figure 2B The details are shown below. The OLED material 112 may include one or more of HIL, HTL, EML, and ETL.

[0026] The choke portion 113 comprises one or more layers. At least one of the layers includes a choke region 113A and a continuous region 113B. The choke portion 113 is disposed above each sub-pixel line PIS 120. The continuous region 113B is disposed on the anode 104 and extends over the upper surface 122 of the PIS 120 and to the sidewall 123 of the PIS 120. The choke region 113A extends along the sidewall 123 and below the adjacent overhang 109, and is accessible to the sidewall 111 of the first structure 110A. A separation edge 124 of the PIS 120 separates the continuous region 113B from the choke region 113A. In one or more embodiments, the choke region 113A and the continuous region 113B are electrically isolated from each other, such that current conducted through the anode 104 is prevented from being conducted to the choke region 113A of the choke portion 113. The choke region 113A acts as a protective layer between the substrate 102 and the cathode. In one or more embodiments, the choke region 113A and the continuous region 113B are physically continuous and electrically separated. In one or more embodiments, the choke region 113A and the continuous region 113B are physically separated and electrically separated. The choke portion 113 extends across a sub-pixel line in the line plane, such as... Figure 1B As shown.

[0027] A continuous portion 114 is disposed above a choke portion 113. The continuous portion 114 extends across both the continuous region 113B and the choke region 113A of the choke portion 113. The choke portion 113 forms a smooth profile on the PIS 120. The smooth profile of the choke portion 113 allows the continuous portion 114 to be deposited continuously without electrical or physical separation. The continuous portion 114 extends across subpixel lines in the line plane, such as... Figure 1B As shown.

[0028] OLED material 112 is disposed below adjacent overhangs 109 and is accessible to the sidewalls 111 of the first structure 110A. In one embodiment, OLED material 112 is different from the materials of the first structure 110A and the second structure 110B. Cathode 115 is disposed above OLED material 112 and extends below adjacent overhangs 109. Choke portions 113 and continuous portions 114 of OLED material 112 form a smooth profile on PIS 120. The smooth profile of OLED material 112 allows cathode 115 to be continuous on OLED material 112 without electrical or physical separation. Choke region 113A acts as a barrier layer between substrate 102 and cathode 115. Cathode 115 may extend through the endpoints of OLED material 112. Cathode 115 contacts the sidewalls 111 of the first structure 110A. The first structure 110A acts as an integral cathode contact of the sub-pixel circuit 100. The overhang structure 110 and the deposition angle defined by the deposition source define the deposition angle, i.e., the overhang structure provides a shielding effect during deposition, wherein the deposition angle is set by the deposition source.

[0029] Cathode 115 comprises a conductive material, such as a metal. For example, cathode 115 includes, but is not limited to, silver, magnesium, chromium, titanium, silicon, aluminum, ITO, or combinations thereof. In one embodiment, the material of cathode 115 differs from the materials of the first structure 110A and the second structure 110B. Cathode 115 extends across a sub-pixel line in a line plane, such as... Figure 1B As shown.

[0030] Each sub-pixel includes an encapsulation layer 116. The encapsulation layer 116 may be or correspond to a local passivation layer. The encapsulation layer 116 of the respective sub-pixel is disposed over the cathode 115 (and OLED material 112), wherein the encapsulation layer 116 extends below at least a portion of each of the adjacent overhangs 109 and extends along the sidewall 111 of each of the first structure 110A and the second structure 110B. The encapsulation layer 116 is disposed over the cathode 115 and extends at least in the pixel plane to contact the cathode 115 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. Figure 1A and Figure 1BIn the illustrated embodiment, the encapsulation layer 116 extends to contact the second structure 110B at the lower surface of the overhang extension 109A, the sidewall 117 of the second structure 110B, and the upper surface 118 of the second structure 110B. In some embodiments, when the OLED material 112 and the cathode 115 are disposed over the sidewall 111 and the upper surface 126 of the second structure 110B, the encapsulation layer 116 extends to contact the second structure 110B at the lower surface of the overhang extension 109A and is disposed over the OLED material 112 and the cathode 115. The encapsulation layer 116 comprises a non-conductive inorganic material, such as a silicon-containing material. The silicon-containing material may include silicon nitride (SiN). x The materials used are silicon dioxide (SiO2) and silicon oxynitride (SiON). In another embodiment, the sub-pixel circuit 100 further includes at least a monolithic passivation layer disposed over the overhang structure 110 and the encapsulation layer 116. The encapsulation layer 116 extends across the sub-pixel line in the line plane, such as... Figure 1B As shown.

[0031] Figure 1C This is a schematic cross-sectional top view of the sub-pixel circuit 100. The sub-pixel circuit 100 includes a plurality of pixel openings 127. Each of the pixel openings 127 is adjacent in the pixel plane by a cantilever structure 110, such as... Figure 1A As shown, this pixel plane defines each of the sub-pixel lines. It is envisioned that, although... Figure 1C OLED material 112, cathode 115, or encapsulation layer 116 are not shown, but it should be understood that this is done for illustrative purposes.

[0032] Figure 2A This is a close-up schematic cross-sectional view of a sub-pixel circuit 100 with a single stacked structure. Figure 2A Section A is a close-up schematic cross-sectional view of a portion of the choke portion 113 of the OLED material 112 having a single stacked structure. The choke portion 113 of the OLED material 112 having a single stacked structure includes a hole injection layer (HIL) 202 and a hole transport layer (HTL) 204. The choke portion 113 may also include a bottom layer. Figure 2A Section B is a close-up schematic cross-sectional view of a portion of a continuous portion 114 of OLED material 112 having a single stacked structure. The continuous portion 114 of OLED material 112 having a single stacked structure includes an emission material layer (EML) 206 and an electron injection layer (EIL) 208. It is envisioned that the continuous layer may include additional layers, such as an electron transport layer (ETL).

[0033] Figure 2BThis is a close-up schematic cross-sectional view of a subpixel circuit 100 with a tandem stacked structure. The tandem stacked structure comprises two or more individual stacked structures deposited on top of each other, wherein a charge generation layer (CGL) is deposited between each stack. Figure 2B Section C is a close-up schematic cross-sectional view of a portion of the choke portion 113 of the OLED material 112 having a tandem stacked structure. The choke portion 113 of the OLED material 112 having a tandem stacked structure includes a first stack 250. The first stack includes HIL 202, HTL 204, EML 206, EIL 208, and CGL 210. Figure 2B Section D is a close-up schematic cross-sectional view of a portion of a continuous portion 114 of OLED material 112 having a tandem stacked structure. The continuous portion 114 of the OLED material 112 with a tandem stacked structure includes a second stack 252. The second stack 252 includes a second HIL 212, a second HTL 214, a second EML 216, and a second EIL 218. It is contemplated that the continuous layers may include additional layers, such as an electron transport layer (ETL). Although... Figure 2B The OLED material 112 is shown to have a tandem stacked structure comprising two stacks, but the continuous portion 114 comprises a single stack. It is contemplated that the continuous portion 114 of the OLED material 112 may include additional stacks, including but not limited to two, three, or four stacks.

[0034] Figure 3 This is a flowchart of a method 300 for forming a sub-pixel circuit 100. Figures 4A to 4D This is a schematic cross-sectional view of a substrate 102 during a method 300 for forming a sub-pixel circuit 100, according to one or more embodiments.

[0035] At operation 301, such as Figure 4A As shown (along the pixel plane), a choke portion 113 of the OLED material 112 is deposited over the anode 104 and the PIS 120. The choke portion 113 includes multiple layers for forming the OLED material 112. If the OLED material 112 is a single stacked structure, the choke portion 113 may include HIL 202 and HTL 204, as... Figure 2A The choke portion 113 may further include an underlying layer if necessary. If the OLED material 112 is a tandem stacked structure, the choke portion 113 may include HIL202, HTL 204, EML 206, EIL 208, and CGL 210, as described above. Figure 2BThe layer described above, constituting the choke portion 113 of the OLED material 112, is deposited during a deposition process. The choke portion 113 is deposited over the anode 104 and the upper surface 122 of the PIS 120. The choke portion 113 extends to the separation edge 124 of the PIS 120. The choke portion 113 is further deposited along the sidewall 123 of the PIS 120 beyond the separation edge. The choke portion 113 is further deposited over the substrate 102 below the adjacent overhang 109 of the overhang structure 110. The separation edge 124 electrically separates the choke portion 113 into a choke region 113A and a continuous region 113B. In one or more embodiments, the choke region 113A and the continuous region 113B are electrically separated but physically connected. In one or more embodiments, the choke region 113A and the continuous region 113B are electrically separated and physically separated by the separation edge 124. The choke region 113A acts as a barrier layer, such as an electrical barrier layer, between the substrate 102 and the cathode 115.

[0036] At operation 302, such as Figure 4B As shown (along the pixel plane), a continuous portion 114 of OLED material 112 is deposited on a choked portion 113 of OLED material 112. The continuous portion 114 includes multiple layers for forming the OLED material 112. If the OLED material 112 is a single stacked structure, the continuous portion 114 may include EML 206 and EIL 208, as... Figure 2A As described above. If the OLED material 112 is a tandem stacked structure, the continuous portion 114 may include a second stack 252 deposited over the first stack 250 of the choke portion 113, as... Figure 2B The second stack 252 may include a second HIL 212, a second HTL 214, a second EML 216, and a second EIL 218, as described above. Figure 2B As described above, the continuous portion 114 of the OLED material 112 having a tandem stacked structure may include additional stacks. The layers described above constituting the continuous portion 114 of the OLED material 112 are deposited during a deposition process. The continuous portion 114 is deposited over a choke portion 113 to form the OLED material 112. The continuous portion 114 extends across both the choke region 113A and the continuous region 113B of the choke portion 113. The choke portion 113 forms a smooth profile on the PIS 120. The smooth profile of the choke portion 113 allows the continuous portion 114 to be deposited continuously without electrical or physical separation.

[0037] At operation 303, such as Figure 4CAs shown (along the pixel plane), cathode 115 is deposited over a continuous portion 114 of OLED material 112. Cathode 115 extends across both the choke region 113A and the continuous region 113B of the choke portion 113. OLED material 112 forms a smooth profile on PIS 120. The smooth profile of OLED material 112 allows cathode 115 to be deposited continuously without electrical or physical separation. Cathode 115 is formed of a silver (Ag) or magnesium (Mg) alloy. The cathode extends above OLED material 112, below adjacent overhangs 109, and contacts the sidewall 111 of first structure 110A. First structure 110A serves as the integral cathode contact of sub-pixel circuit 100.

[0038] At operation 304, such as Figure 4D As shown (along the pixel plane), an encapsulation layer 116 is deposited over the cathode 115 and the overhang structure 110. The encapsulation layer 116 is disposed over the cathode 115 and extends in the pixel plane to contact the cathode 115 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. Figure 1A and Figure 1B In the illustrated embodiment, the encapsulation layer 116 extends to contact the second structure 110B at the lower surface of the overhang extension 109A, the sidewall 117 of the second structure 110B, and the upper surface 118 of the second structure 110B. In some embodiments, when the OLED material 112 and the cathode 115 are disposed over the sidewall 111 and the upper surface 126 of the second structure 110B, the encapsulation layer 116 extends to contact the second structure 110B at the lower surface of the overhang extension 109A and is disposed over the OLED material 112 and the cathode 115. In another embodiment, the sub-pixel circuit 100 further includes at least an integral passivation layer disposed over the overhang structure 110 and the encapsulation layer 116. The encapsulation layer 116 extends across the sub-pixel line in the line plane, as shown below. Figure 1B As shown.

[0039] The benefits of this disclosure include sub-pixel circuitry with integral cathode contacts. The increased thickness of the PIS 120 allows a portion of the OLED material 112 to be choked. The choked portion 113 of the OLED material acts as a barrier layer between the substrate 102 and the cathode 115. The choked portion 113 allows the cathode 115 to contact the sidewall 111 of the first structure 110A of the overhang structure 110. The first structure 110A is formed of a conductive material and acts as an integral cathode contact of the sub-pixel circuitry 100. Generally, the sub-pixel architecture described herein allows for increased deposition tolerances for both the OLED material 112 and the cathode 115. The cathode 115 portion contacting the sidewall 111 has increased tolerances because the choked portion 113 acts as a barrier layer between the cathode 115 and the substrate 102. Additionally, the deposition angle between the OLED material 112 and the cathode 115 can be larger due to less required deposition control. The devices and methods of forming the devices described herein allow for the fabrication of sub-pixel circuitry without localized cathode contacts, which significantly reduces the manufacturing cost of large OLED devices.

[0040] It is envisioned that one or more aspects disclosed herein may be combined. For example, one or more aspects, features, components, operations, and / or properties of subpixel circuit 100, substrate 102, anode 104, PIS 120, OLED material 112, choke portion 113, continuity portion 114, cathode 115, encapsulation layer 116, overhang structure 110, first structure 110A, second structure 110B, opening 125, first stack 250, second stack 252, HIL 202, HTL 204, EML 206, EIL 208, CGL 210, second HIL 212, second HTL 214, second EML, second EIL, and / or method 300 may be combined. Furthermore, it is envisioned that one or more aspects disclosed herein may include some or all of the foregoing benefits.

[0041] While the foregoing describes embodiments of this disclosure, other and further embodiments of this disclosure may be conceived without departing from the basic scope of this disclosure, and the scope of this disclosure is defined by the appended claims.

Claims

1. A sub-pixel, comprising: Adjacent overhanging structures are disposed above a substrate, each overhanging structure having an overhanging extension that extends laterally upward through the sidewall of each overhanging structure. A pixel isolation structure (PIS) is disposed above the substrate and between adjacent overhang structures, the PIS including an upper surface and at least two sidewalls opposite each other; Anode, which is disposed on the PIS; as well as An OLED material, disposed above the anode and extending above the upper surface and sidewalls of the PIS, wherein the OLED material further extends below the overhanging extension, the OLED material comprising: The choke portion has one or more layers, at least one of the one or more layers comprising: A continuous region, the continuous region being disposed above the anode and the upper surface of the PIS; and A choke region, the choke region being disposed above the sidewall and extending below the overhanging extension, wherein the choke region and the continuous region of the at least one layer are electrically separated from each other; A continuous portion, said continuous portion being disposed above the choke portion; and The cathode is disposed above the OLED material.

2. The sub-pixel of claim 1, wherein one or more layers of the choke portion comprise: Hole injection layer; or A hole transport layer is disposed above the hole injection layer.

3. The sub-pixel of claim 2, wherein the continuous portion comprises: Emission material layer; as well as An electron injection layer is disposed above the emission material layer.

4. The sub-pixel of claim 1, wherein one or more layers of the choke portion comprise: First hole injection layer; A first hole transport layer is disposed above the first hole injection layer; A first emission material layer is disposed above the first hole transport layer; A first electron injection layer is disposed above the first emission material layer; or A charge generation layer is disposed above the first electron injection layer.

5. The sub-pixel of claim 4, wherein the continuous portion comprises: Second cavity injection layer; A second hole transport layer is disposed above the second hole injection layer; A second emission material layer is disposed above the second hole transport layer; as well as The second electron injection layer is disposed above the second emission material layer.

6. The sub-pixel of claim 1, wherein the PIS has a height of about 200 nm to about 300 nm.

7. The sub-pixel of claim 1, wherein at least a portion of the OLED material contacts the sidewall of each of the adjacent overhang structures.

8. The sub-pixel of claim 1, wherein at least a portion of the cathode contacts the sidewall of each of the adjacent overhang structures.

9. The sub-pixel of claim 1, wherein the PIS further includes an opening extending from the upper surface of the PIS to the lower surface of the PIS.

10. The sub-pixel of claim 9, wherein at least a portion of the anode is deposited within the opening.

11. A sub-pixel, comprising: Adjacent overhang structures, wherein the adjacent overhang structures are disposed above the substrate along a line plane, the adjacent overhang structures comprising: A first structure, wherein the first structure is disposed on the substrate; and A second structure is disposed on the first structure, wherein the bottom surface side of the second structure extends upward through the upper surface of the first structure, thereby defining the overhang extension; A pixel isolation structure (PIS) is disposed on the substrate and extends along the line plane between adjacent overhang structures. The PIS includes a top surface and a plurality of sidewalls. Anode, which is positioned above the PIS; An OLED material, disposed on the anode and extending over the upper surface of the PIS and the plurality of sidewalls, the OLED material further extending below the overhanging extension, the OLED material comprising: The choke portion includes: A continuous region, the continuous region being disposed above the anode and the upper surface of the PIS; and A choke region is disposed above the plurality of sidewalls and extends below the overhanging extension, wherein the choke region and the continuous region are electrically isolated from each other; A continuous portion, said continuous portion being disposed above the choke portion; and The cathode is disposed above the OLED material.

12. The sub-pixel of claim 11, wherein the choke portion comprises: Hole injection layer; as well as A hole transport layer is disposed above the hole injection layer.

13. The sub-pixel of claim 12, wherein the continuous portion comprises: Emission material layer; as well as An electron injection layer is disposed above the emission material layer.

14. The sub-pixel of claim 11, wherein the choke portion comprises: First hole injection layer; A first hole transport layer is disposed above the first hole injection layer; A first emission material layer is disposed above the first hole transport layer; A first electron injection layer is disposed above the first emission material layer; as well as A charge generation layer is disposed above the first electron injection layer.

15. The sub-pixel of claim 14, wherein the continuous portion comprises: Second cavity injection layer; A second hole transport layer is disposed above the second hole injection layer; A second emission material layer is disposed above the second hole transport layer; as well as The second electron injection layer is disposed above the second emission material layer.

16. The sub-pixel of claim 11, wherein the PIS has a height of about 200 nm to about 300 nm.

17. The sub-pixel of claim 11, wherein at least a portion of the OLED material contacts the first structure of each of the adjacent overhang structures.

18. The sub-pixel of claim 11, wherein at least a portion of the cathode contacts the first structure of each of the adjacent overhang structures.

19. The sub-pixel of claim 11, wherein the PIS further includes an opening extending from the upper surface of the PIS to the lower surface of the PIS, and at least a portion of the anode is deposited within the opening.

20. A device comprising: Multiple subpixel lines, each subpixel line comprising at least one subpixel, said at least one subpixel comprising: Adjacent overhang structures, wherein the adjacent overhang structures are disposed on the substrate along a line plane, the adjacent overhang structures comprising: A first structure, wherein the first structure is disposed on the substrate; and A second structure is disposed on the first structure, wherein the bottom surface side of the second structure extends upward through the upper surface of the first structure, thereby defining the overhang extension; A pixel isolation structure (PIS) is disposed on the substrate and extends along the line plane between adjacent overhang structures. The PIS includes a top surface and a plurality of sidewalls. Anode, which is disposed on the PIS; An OLED material, disposed above the anode and extending above the upper surface of the PIS and the plurality of sidewalls, the OLED material further extending below the overhanging extension, the OLED material comprising: The choke portion includes: A continuous region, the continuous region being disposed above the anode and the upper surface of the PIS; and A choke region is disposed above the plurality of sidewalls and extends below the overhanging extension, wherein the choke region and the continuous region are electrically isolated from each other; A continuous portion, wherein the continuous portion is disposed above the choke portion; Cathode, the cathode being disposed above the OLED material; and An encapsulation layer is disposed above the cathode.

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