# US 12,120,901 B2 · Light-emitting element for efficiently emitting light in different colors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,901 B2 - Document ID: US12120901B2 - Status: Granted - Kind: B2 - Application number: 17/289,208 - Filed: 2018-10-30 - Published: 2022-01-13 - Granted: 2024-10-15 - Earliest claimed: 2018-10-30 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: Yusuke Sakakibara; Tatsuya Ryohwa - Web page: https://patentgrep.com/patent/US12120901B2 ## CPC - H10K 50/16: Electron transporting layers - H05B 33/10: Apparatus or processes specially adapted to the manufacture of electroluminescent light sources - H05B 33/12: Light sources with substantially two-dimensional [2D] radiating surfaces - H05B 33/14: characterised by the chemical or physical composition or the arrangement of the electroluminescent material {, or by the simultaneous addition of the electroluminescent material in or onto the light source} - H05B 33/26: characterised by the composition or arrangement of the conductive material used as an electrode - H10K 50/115: comprising active inorganic nanostructures, e.g. luminescent quantum dots - H10K 50/15: Hole transporting layers - H10K 59/35: comprising red-green-blue [RGB] subpixels - H10K 2102/351: {Thickness} - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract Provided is a light-emitting element to highly efficiently emit light in different colors. The light-emitting element includes: a cathode; an anode; a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions respectively emitting light of different wavelengths; and an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions each corresponding to one of the light-emitting regions. The electron-transport layer includes a Zn1-XMgXO film (where X is 0≤X<1). Of the plurality of regions included in the electron-transport layer, a region, corresponding to one of the light-emitting regions that emits light of a shorter wavelength, is higher in composition ratio X of Mg and/or less in thickness of the Zn1-XMgXO film. ## Claims ### Claim 1 A light-emitting element, comprising: a cathode; an anode; a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions, respectively, emitting light of different wavelengths; and an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions, each of the plurality of regions corresponding to one of the plurality of light-emitting regions, the electron-transport layer including a Zn1-XMgXO film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to the one of the plurality of light-emitting regions that emits light of a shorter wavelength, being higher in a composition ratio X of Mg and less in a thickness of the Zn1-XMgXO film. ### Claim 2 A light-emitting element, comprising: a cathode; an anode; a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions, respectively, emitting light of different wavelengths; and an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions, each of the plurality of regions corresponding to one of the plurality of light-emitting regions, the electron-transport layer including a Zn1-XMgXO film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to the one of the plurality of light-emitting regions that emits light of a shorter wavelength, being higher in a composition ratio X of Mg. ### Claim 3 (depends on 2) The light-emitting element according to claim 2, wherein the plurality of light-emitting regions includes a red light emitting region emitting red light, a green light emitting region emitting green light, and a blue light emitting region emitting blue light. ### Claim 4 (depends on 3) The light-emitting element according to claim 3, wherein of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, contains Mg having the composition ratio X of 0 or higher and lower than 0.05, a region, corresponding to the green light emitting region, contains Mg having the composition ratio X of 0.05 or higher and lower than 0.15, and a region, corresponding to the blue light emitting region, contains Mg having the composition ratio X of 0.15 or higher and lower than 0.25. ### Claim 5 (depends on 3) The light-emitting element according to claim 3, wherein of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, includes the Zn1-XMgXO film having a thickness of 45 nm or more and less than 55 nm, a region, corresponding to the green light emitting region, includes the Zn1-XMgXO film having the thickness of 35 nm or more and less than 45 nm, and a region, corresponding to the blue light emitting region, includes the Zn1-XMgXO film having the thickness of 25 nm or more and less than 35 nm. ### Claim 6 (depends on 2) The light-emitting element according to claim 2, wherein the light-emitting layer contains quantum dots. ### Claim 7 (depends on 2) The light-emitting element according to claim 2, further comprising: a hole-transport layer formed between the anode and the light-emitting layer, wherein the hole-transport layer includes a single region corresponding to two or more of the plurality of light-emitting regions. ### Claim 8 (depends on 2) The light-emitting element according to claim 2, wherein at least one selected from the cathode and the anode is formed into a single region corresponding to all of the plurality of light-emitting regions, and is disposed on a substrate. ### Claim 9 (depends on 2) The light-emitting element according to claim 2, wherein both the cathode and the anode are formed into a single region corresponding to all of the plurality of light-emitting regions. ### Claim 10 A light-emitting element, comprising: a cathode; an anode; a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting region, respectively, emitting light of different wavelengths; and an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of region, each of the plurality of regions corresponding to one of the plurality of light-emitting regions, the electron-transport layer including a Zn1-XMgXO film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to the one of the plurality of light-emitting regions that emits light of a shorter wavelength, being less in a thickness of the Zn1-XMgXO film, wherein the light-emitting layer includes a red light emitting region emitting red light, a green light emitting region emitting green light, and a blue light emitting region emitting blue light, and of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, contains Mg having a composition ratio X of 0 or higher and lower than 0.05, a region, corresponding to the green light emitting region, contains Mg having the composition ratio X of 0.05 or higher and lower than 0.15, and a region, corresponding to the blue light emitting region, contains Mg having the composition ratio X of 0.15 or higher and lower than 0.25. ### Claim 11 (depends on 10) The light-emitting element according to claim 10, wherein the light-emitting layer contains quantum dots. ### Claim 12 (depends on 10) The light-emitting element according to claim 10, further comprising: a hole-transport layer formed between the anode and the light-emitting layer, wherein the hole-transport layer includes a single region corresponding to two or more of the plurality of light-emitting regions. ### Claim 13 (depends on 10) The light-emitting element according to claim 10, wherein at least one selected from the cathode and the anode is formed into a single region corresponding to all of the plurality of light-emitting regions, and is disposed on a substrate. ### Claim 14 (depends on 10) The light-emitting element according to claim 10, wherein both the cathode and the anode are formed into a single region corresponding to all of the plurality of light-emitting regions. ### Claim 15 A light-emitting element, comprising: a cathode; an anode; a light-emitting layer formed between the cathode and the anode, and including a plurality of light-emitting regions, respectively, emitting light of different wavelengths; and an electron-transport layer formed between the cathode and the light-emitting layer, and including a plurality of regions, each of the plurality of regions corresponding to one of the plurality of light-emitting regions, the electron-transport layer including a Zn1-XMgXO film (where 0≤X<1), and, of the plurality of regions included in the electron-transport layer, a region, corresponding to one of the plurality of light-emitting regions that emits light of a shorter wavelength, being less in a thickness of the Zn1-XMgXO film, wherein the light-emitting layer includes a red light emitting region emitting red light, a green light emitting region emitting green light, and a blue light emitting region emitting blue light, and of the plurality of regions included in the electron-transport layer, a region, corresponding to the red light emitting region, includes the Zn1-XMgXO film having the thickness of 45 nm or more and less than 55 nm, the region a region, corresponding to the green light emitting region-region, includes the Zn1-xMgxO film having the thickness of 35 nm or more and less than 45 nm, and a region, corresponding to the blue light emitting region, includes the Zn1-XMgXO film having the thickness of 25 nm or more and less than 35 nm. ### Claim 16 (depends on 15) The light-emitting element according to claim 15, wherein the light-emitting layer contains quantum dots. ### Claim 17 (depends on 15) The light-emitting element according to claim 15, further comprising: a hole-transport layer formed between the anode and the light-emitting layer, wherein the hole-transport layer includes a single region corresponding to two or more of the plurality of light-emitting regions. ### Claim 18 (depends on 15) The light-emitting element according to claim 15, wherein at least one selected from the cathode and the anode is formed into a single region corresponding to all of the plurality of light-emitting regions, and is disposed on a substrate. ### Claim 19 (depends on 15) The light-emitting element according to claim 15, wherein both the cathode and the anode are formed into a single region corresponding to all of the plurality of light-emitting regions.