# US 9,437,824 B2 · Light-emitting element, light emitting device, and electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,437,824 B2 - Document ID: US9437824B2 - Status: Granted - Kind: B2 - Application number: 13/748,844 - Filed: 2013-01-24 - Published: 2013-05-30 - Granted: 2016-09-06 - Earliest claimed: 2008-12-17 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Takahiro Ushikubo; Satoshi Seo; Nobuharu Ohsawa - Web page: https://patentgrep.com/patent/US9437824B2 ## CPC - H10K 85/615: {Polycyclic condensed aromatic hydrocarbons, e.g. anthracene} - 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} - H10K 50/125: specially adapted for multicolour light emission, e.g. for emitting white light - H10K 85/633: {comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom} - H10K 85/6572: {comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole} - 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 A light-emitting element includes a light-emitting layer having a two-layer structure in which a first light-emitting layer containing a first light-emitting substance and a second light-emitting layer containing a second light-emitting substance, which is in contact with the first light-emitting layer, are provided between an anode and a cathode. The first light-emitting layer is separated into two layers of a layer provided on the anode side and a layer provided on the cathode side. The layer provided on the anode side contains only a first light-emitting substance, or a first organic compound of less than 50 wt % and the first light-emitting substance of 50 wt % to 100 wt %. The layer provided on the cathode side contains a second organic compound and the first light-emitting substance. The second light-emitting layer, which is provided in contact with the first light-emitting layer, contains the second light-emitting substance and a third organic compound. ## Claims ### Claim 1 A light-emitting element comprising: a first light-emitting layer between an anode and a cathode; and a second light-emitting layer between the anode and the cathode, the second light-emitting layer being in contact with a cathode side of the first light-emitting layer, wherein the first light-emitting layer includes a first layer provided on an anode side and a second layer provided on a cathode side, wherein the first layer provided on the anode side contains a first light-emitting substance and a first organic compound, wherein the second layer provided on the cathode side contains a second organic compound and the first light-emitting substance, wherein an amount of the second organic compound in the second layer provided on the cathode side is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, wherein the second light-emitting layer contains a third organic compound and a second light-emitting substance, wherein an amount of the third organic compound in the second light-emitting layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, and wherein the first organic compound is a compound different from the second organic compound. ### Claim 2 (depends on 1) The light-emitting element according to claim 1, wherein the first layer provided on the anode side has a hole-transporting property; wherein the second layer provided on the cathode side has an electron-transporting property; and wherein the second light-emitting layer has an electron-transporting property. ### Claim 3 (depends on 1) The light-emitting element according to claim 1, wherein the first light-emitting substance has a hole-transporting property; wherein the second organic compound has an electron-transporting property; and wherein the third organic compound has an electron-transporting property. ### Claim 4 (depends on 1) The light-emitting element according to claim 1, wherein the first light-emitting substance is represented by a general formula (i); and wherein Ar1 represents an aryl group having 6 to 25 carbon atoms, Ar2 represents an arylene group having 6 to 25 carbon atoms, and Ar3 and Ar4 independently represent either an aryl group having 6 to 25 carbon atoms or a carbazolyl group. ### Claim 5 (depends on 1) The light-emitting element according to claim 1, wherein an emission peak wavelength of the first light-emitting substance is shorter than an emission peak wavelength of the second light-emitting substance. ### Claim 6 (depends on 1) The light-emitting element according to claim 1, wherein an emission color of the first light-emitting substance and an emission color of the second light-emitting substance complement each other. ### Claim 7 (depends on 1) The light-emitting element according to claim 1, wherein an emission color of the first light-emitting substance is blue and an emission color of the second light-emitting substance is yellow, wherein an emission color of the first light-emitting substance is blue green and an emission color of the second light-emitting substance is red, or wherein an emission color of the first light-emitting substance is blue and an emission color of the second light-emitting substance is green. ### Claim 8 (depends on 1) The light-emitting element according to claim 1, wherein an emission peak wavelength of the first light-emitting substance is in a range of greater than or equal to 400 nm and less than 480 nm, and an emission peak wavelength of the second light-emitting substance is in a range of greater than or equal to 540 nm and less than 600 nm. ### Claim 9 (depends on 1) A lighting device comprising the light-emitting element according to claim 1. ### Claim 10 (depends on 1) The light-emitting element according to claim 1, wherein the first layer provided on the anode side consists essentially of the first light-emitting substance. ### Claim 11 (depends on 1) The light-emitting element according to claim 1, wherein both light emission from the first light-emitting substance and light emission from the second light-emitting substance can be obtained. ### Claim 12 A light-emitting element comprising: a first light-emitting layer between an anode and a cathode; and a second light-emitting layer between the anode and the cathode, the second light-emitting layer being in contact with a cathode side of the first light-emitting layer, wherein the first light-emitting layer includes a first layer provided on an anode side and a second layer provided on a cathode side, wherein the first layer provided on the anode side contains a first organic compound and a first light-emitting substance, wherein an amount of the first light-emitting substance in the first layer provided on the anode side is greater than or equal to 50 wt % and less than 100 wt %, wherein the second layer provided on the cathode side contains a second organic compound and the first light-emitting substance, wherein an amount of the second organic compound in the second layer provided on the cathode side is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, wherein the second light-emitting layer contains a third organic compound and a second light-emitting substance, wherein an amount of the third organic compound in the second light-emitting layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, and wherein the first organic compound is a compound different from the second organic compound. ### Claim 13 (depends on 12) The light-emitting element according to claim 12, wherein the first layer provided on the anode side has a hole-transporting property; wherein the second layer provided on the cathode side has an electron-transporting property; and wherein the second light-emitting layer has an electron-transporting property. ### Claim 14 (depends on 12) The light-emitting element according to claim 12, wherein the first light-emitting substance has a hole-transporting property; wherein the second organic compound has an electron-transporting property; and wherein the third organic compound has an electron-transporting property. ### Claim 15 (depends on 12) The light-emitting element according to claim 12, wherein the first light-emitting substance is represented by a general formula (i); and wherein Ar2 represents an aryl group having 6 to 25 carbon atoms, Are represents an arylene group having 6 to 25 carbon atoms, and Ar3 and Ar4 independently represent either an aryl group having 6 to 25 carbon atoms or a carbazolyl group. ### Claim 16 (depends on 12) The light-emitting element according to claim 12, wherein an emission peak wavelength of the first light-emitting substance is shorter than an emission peak wavelength of the second light-emitting substance. ### Claim 17 (depends on 12) The light-emitting element according to claim 12, wherein an emission color of the first light-emitting substance and an emission color of the second light-emitting substance complement each other. ### Claim 18 (depends on 12) The light-emitting element according to claim 12, wherein an emission color of the first light-emitting substance is blue and an emission color of the second light-emitting substance is yellow, wherein an emission color of the first light-emitting substance is blue green and an emission color of the second light-emitting substance is red, or wherein an emission color of the first light-emitting substance is blue and an emission color of the second light-emitting substance is green. ### Claim 19 (depends on 12) The light-emitting element according to claim 12, wherein an emission peak wavelength of the first light-emitting substance is in a range of greater than or equal to 400 nm and less than 480 nm, and an emission peak wavelength of the second light-emitting substance is in a range of greater than or equal to 540 nm and less than 600 nm. ### Claim 20 (depends on 12) A lighting device comprising the light-emitting element according to claim 12. ### Claim 21 (depends on 12) The light-emitting element according to claim 12, wherein both light emission from the first light-emitting substance and light emission from the second light-emitting substance can be obtained. ### Claim 22 A light-emitting element comprising: a first light-emitting layer between an anode and a cathode; a second light-emitting layer between the anode and the cathode, the second light-emitting layer being in contact with a cathode side of the first light-emitting layer, wherein the first light-emitting layer includes a first layer provided on an anode side and a second layer provided on a cathode side, wherein the first layer provided on the anode side contains a first light-emitting substance and a first organic compound, wherein the first light-emitting substance has a hole-transporting property, wherein an amount of the first light-emitting substance in the first layer provided on the anode side is greater than or equal to 200/3 wt % and less than 100 wt %, wherein the second layer provided on the cathode side contains a second organic compound and the first light-emitting substance, wherein an amount of the second organic compound in the second layer provided on the cathode side is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, wherein the second light-emitting layer contains a third organic compound and a second light-emitting substance, wherein an amount of the third organic compound in the second light-emitting layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, and wherein the first organic compound is a compound different from the second organic compound. ### Claim 23 (depends on 22) The light-emitting element according to claim 22, wherein the second layer and the first layer are in contact with each other, and wherein the second layer has an electron-transporting property. ### Claim 24 (depends on 22) The light-emitting element according to claim 22, wherein the first light-emitting substance is represented by a general formula (i); and wherein Ar1 represents an aryl group having 6 to 25 carbon atoms, Ar2 represents an arylene group having 6 to 25 carbon atoms, and Ar3 and Ar4 independently represent either an aryl group having 6 to 25 carbon atoms or a carbazolyl group. ### Claim 25 (depends on 22) A lighting device comprising the light-emitting element according to claim 22. ### Claim 26 A light-emitting element comprising: a first light-emitting layer between an anode and a cathode; and a second light-emitting layer between the anode and the cathode, the second light-emitting layer being in contact with a cathode side of the first light-emitting layer, wherein the first light-emitting layer includes a first provided on an anode side and a second layer provided on a cathode side, wherein the first layer provided on an anode side contains a first light-emitting substance and a first organic compound, wherein the second layer provided on the cathode side contains a second organic compound and the first light-emitting substance, wherein an amount of the second organic compound in the second layer provided on the cathode side is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, wherein the second light-emitting layer contains a third organic compound and a second light-emitting substance, wherein an amount of the third organic compound in the second light-emitting layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, wherein the first organic compound is a compound different from the second organic compound, wherein the first layer has a hole-transporting property higher than the second layer, wherein the second layer has an electron-transporting property higher than the first layer, and wherein a thickness of the second layer is smaller than a thickness of the first layer. ### Claim 27 (depends on 26) The light-emitting element according to claim 26, wherein the first layer and the second layer are in contact with each other. ### Claim 28 (depends on 26) The light-emitting element according to claim 26, wherein the second layer and the second light-emitting layer are in contact with each other. ### Claim 29 (depends on 26) The light-emitting element according to claim 26, wherein the first light-emitting substance is represented by a general formula (i); and wherein Ar1 represents an aryl group having 6 to 25 carbon atoms, Ar2 represents an arylene group having 6 to 25 carbon atoms, and Ara and Ar4 independently represent either an aryl group having 6 to 25 carbon atoms or a carbazolyl group. ### Claim 30 (depends on 26) A lighting device comprising the light-emitting element according to claim 26.