# US 12,016,191 B2 · Electronic device including a light-emitting element having functional layers with thickness profiles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,016,191 B2 - Document ID: US12016191B2 - Status: Granted - Kind: B2 - Application number: 17/341,205 - Filed: 2021-06-07 - Published: 2022-03-17 - Granted: 2024-06-18 - Earliest claimed: 2020-09-11 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Soohyun Park; Donghoon Kwak; Seulgi Han - Web page: https://patentgrep.com/patent/US12016191B2 ## CPC - H10K 59/121: characterised by the geometry or disposition of pixel elements - H10K 50/11: characterised by the electroluminescent [EL] layers - H10K 50/15: Hole transporting layers - H10K 59/122: Pixel-defining structures or layers, e.g. banks - H10K 50/17: Carrier injection layers - H10K 59/35: comprising red-green-blue [RGB] subpixels - H10K 2101/40: Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers - H10K 2102/351: {Thickness} - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract An electronic device includes a base layer, a first electrode disposed on the base layer, a pixel defining layer disposed on the base layer and having an opening that exposes an upper surface of the first electrode, a hole transport region disposed in the opening and having a thickness that gradually decreases from a center of the opening toward a side surface of the pixel defining layer, an emission layer disposed on the hole transport region and having a thickness that gradually increases from the center of the opening toward the side surface of the pixel defining layer, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. This electronic device may increase a light-emitting area exhibiting uniform (or substantially uniform) light-emitting characteristics and exhibit high light-emitting efficiency. ## Claims ### Claim 1 An electronic device comprising: a base layer; a first electrode on the base layer; a pixel defining layer on the base layer and having an opening that exposes an upper surface of the first electrode; a hole transport region in the opening and having a thickness gradually decreasing from a center of the opening toward a side surface of the pixel defining layer; an emission layer directly on the hole transport region and having a thickness gradually increasing from the center of the opening toward the side surface of the pixel defining layer; an electron transport region on the emission layer; and a second electrode on the electron transport region, wherein the emission layer comprises a host and a dopant. ### Claim 2 (depends on 1) The electronic device of claim 1, wherein a first average thickness in a first portion of the hole transport region is greater than a second average thickness in a second portion of the hole transport region, the first portion is 60% of a total cross-sectional area of the hole transport region, with a virtual center line passing through the center of the hole transport region as the center line of the total cross-sectional area in the thickness direction of the hole transport region, the second portion is 80% of the total cross-sectional area of the hole transport region, and wherein a value of the first average thickness is a cross-sectional area of the first portion divided by a width of the first portion, and a value of the second average thickness is a cross-sectional area of the second portion dived by a width of the second portion. ### Claim 3 (depends on 2) The electronic device of claim 2, wherein an upper surface of the hole transport region is a curved surface convex toward the emission layer. ### Claim 4 (depends on 1) The electronic device of claim 1, wherein a first average thickness in a first portion of the emission layer is smaller than a second average thickness in a second portion of the emission layer, the first portion is 60% of a total cross-sectional area of the emission layer, with a virtual center line passing through the center of the emission layer as the center line of the total cross-sectional area in the thickness direction of the emission layer, the second portion is 80% of the total cross-sectional area of the emission layer, and wherein a value of the first average thickness is a cross-sectional area of the first portion divided by a width of the first portion, and a value of the second average thickness is a cross-sectional area of the second portion divided by a width of the second portion. ### Claim 5 (depends on 4) The electronic device of claim 4, wherein a lower surface of the emission layer is a curved surface concave toward an upper surface of the emission layer, and the upper surface of the emission layer is a flat surface. ### Claim 6 (depends on 1) The electronic device of claim 1, wherein a percentage difference between a sum of a thickness of a first portion of the hole transport region measured at a virtual center line, which passes through the center of the opening and is normal to the first electrode, and a thickness of a second portion of the emission layer measured at the virtual center line, and a sum of a thickness of a third portion of the hole transport region and a thickness of a fourth portion of the emission layer respectively measured at a virtual outer peripheral line parallel to the virtual center line, is less than about 10%. ### Claim 7 (depends on 1) The electronic device of claim 1, wherein the hole transport region comprises a hole injection layer on the first electrode; and a hole transport layer on the hole injection layer, the hole injection layer and having a thickness gradually decreasing from the center of the opening toward the side surface of the pixel defining layer. ### Claim 8 (depends on 7) The electronic device of claim 7, wherein the hole transport layer has a thickness gradually decreasing from the center of the opening toward the side surface of the pixel defining layer. ### Claim 9 (depends on 7) The electronic device of claim 7, wherein an upper surface of the hole injection layer is a curved surface convex toward the emission layer, and an upper surface of the hole transport layer is a curved surface convex toward the emission layer. ### Claim 10 (depends on 1) The electronic device of claim 1, wherein a resistivity of the hole transport region is lower than a resistivity of the emission layer. ### Claim 11 (depends on 10) The electronic device of claim 10, wherein the resistivity of the emission layer is about 10 times to about 100 times the resistivity of the hole transport region. ### Claim 12 (depends on 1) The electronic device of claim 1, wherein the side surface of the pixel defining layer defining the opening is hydrophobic. ### Claim 13 (depends on 1) The electronic device of claim 1, wherein the hole transport region and the emission layer are provided by an inkjet printing method, and the electron transport region is provided by a deposition method. ### Claim 14 An electronic device comprising: a pixel defining layer in which a plurality of openings spaced apart from each other on a plane are defined; and a plurality of light-emitting elements comprising at least one functional layer in each of the plurality of openings, wherein each of the plurality of light-emitting elements comprises: a first electrode, at least a portion of the first electrode being in direct contact with at least a portion of the pixel defining layer; a hole transport region on the first electrode and being greater in thickness at a center of the hole transport region than at an outer periphery thereof; an emission layer on the hole transport region and being smaller in thickness at a center of the emission layer than at an outer periphery thereof; an electron transport region on the emission layer; and a second electrode on the electron transport region, and wherein the center of the hole transport region and the center of the emission layer respectively correspond to a point that passes through a virtual center line normal to the first electrode, and the outer periphery of the hole transport region and the outer periphery of the emission layer respectively correspond to a point spaced apart from the center toward the pixel defining layer. ### Claim 15 (depends on 14) The electronic device of claim 14, wherein the at least one functional layer is provided by an inkjet printing method. ### Claim 16 (depends on 14) The electronic device of claim 14, wherein an upper surface of the hole transport region is a curved surface convex toward the emission layer. ### Claim 17 (depends on 16) The electronic device of claim 16, wherein a shape of a lower surface of the emission layer corresponds to a shape of the upper surface of the hole transport region, and an upper surface of the emission layer is a flat surface. ### Claim 18 (depends on 16) The electronic device of claim 16, wherein in the plurality of openings, a difference between a first thickness from the first electrode to an upper portion of the emission layer at a center of an opening of the plurality of openings and a second thickness from the first electrode to the upper portion of the emission layer at an outer periphery of the opening is less than about 10%. ### Claim 19 An electronic device comprising a plurality of light-emitting elements, each of the plurality of light-emitting elements comprising: a first electrode; a hole transport region on the first electrode; an emission layer directly on the hole transport region, the emission layer comprising a host and a dopant; an electron transport region on the emission layer; and a second electrode on the electron transport region, wherein a first thickness of the hole transport region, which is a distance between the first electrode and the emission layer, decreases from a center of the hole transport region to an outer periphery thereof, and a second thickness of the emission layer, which is a distance between the hole transport region and the electron transport region, increases from a center of the emission layer to an outer periphery thereof. ### Claim 20 (depends on 19) The electronic device of claim 19, wherein an upper surface of the hole transport region is a curved surface convex toward the emission layer, and a shape of a lower surface of the emission layer corresponds to a shape of the upper surface of the hole transport region, and an upper surface of the emission layer is a flat surface.