# US 10,764,974 B2 · Light-emitting device using organometallic complex having a pyrazine skeleton > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,764,974 B2 - Document ID: US10764974B2 - Status: Granted - Kind: B2 - Application number: 16/157,497 - Filed: 2018-10-11 - Published: 2019-02-14 - Granted: 2020-09-01 - Earliest claimed: 2006-11-30 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Nobuharu Ohsawa; Hideko Inoue; Satoshi Seo - Web page: https://patentgrep.com/patent/US10764974B2 ## CPC - 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} - C09K 11/06: containing organic luminescent materials - H10K 50/11: characterised by the electroluminescent [EL] layers - H10K 85/342: {comprising iridium} - C09K 2211/1007: Non-condensed systems - C09K 2211/1011: Condensed systems - C09K 2211/1029: containing one nitrogen atom as the heteroatom - C09K 2211/1044: containing two nitrogen atoms as heteroatoms - C09K 2211/185: of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd - H10K 85/324: {comprising aluminium, e.g. Alq3} - 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 2101/10: Triplet emission - H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values - H10K 2101/90: {Multiple hosts in the emissive layer} - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract Light-emitting elements having high emission efficiency and long lifetime can be provided. By forming light-emitting devices including the light-emitting elements, the light-emitting devices having low power consumption and long lifetime can be provided. A light-emitting device comprises a light-emitting element including a light-emitting layer between a first electrode and a second electrode. The light-emitting layer includes a first organic compound having a hole-transporting property, a second organic compound having an electron transporting property, and an organometallic complex. A central metal of the organometallic complex is an element belonging to one of Group 9 and Group 10, and a ligand of the organometallic complex is a ligand having a pyrazine skeleton. ## Claims ### Claim 1 A light-emitting device comprising: a first electrode; a hole transporting layer over the first electrode; a light-emitting layer over the hole transporting layer; an electron transporting layer over the light-emitting layer; and a second electrode over the electron transporting layer, wherein the light-emitting layer includes a first organic compound having a hole-transporting property, a second organic compound having an electron transporting property, and an organometallic complex, wherein a central metal of the organometallic complex comprises an element belonging to one of Group 9 and Group 10, wherein a ligand of the organometallic complex comprises a pyrazine skeleton, and wherein an amount of the second organic compound is equal to or higher than an amount of the first organic compound. ### Claim 2 (depends on 1) The light-emitting device according to claim 1, wherein the ligand comprises a 2-arylpyrazine derivative. ### Claim 3 (depends on 1) The light-emitting device according to claim 1, wherein the ligand comprises a 2-phenylpyrazine derivative. ### Claim 4 (depends on 1) The light-emitting device according to claim 1, wherein the ligand comprises a 2,5-diphenylpyrazine derivative. ### Claim 5 (depends on 1) The light-emitting device according to claim 1, wherein the central metal comprises one of iridium and platinum, the first organic compound comprises one of an aromatic amine compound and a carbazole derivative, and the second organic compound comprises one of a heteroaromatic compound and a metal complex. ### Claim 6 (depends on 1) The light-emitting device according to claim 1, wherein an amount of the organometallic complex in the light-emitting layer is greater than or equal to 1 percent by mass and less than or equal to 10 percent by mass. ### Claim 7 (depends on 1) The light-emitting device according to claim 1, wherein a mass ratio of the second organic compound to the first organic compound is 1 to 20 inclusive. ### Claim 8 (depends on 1) The light-emitting device according to claim 1, wherein a LUMO level of the organometallic complex is deeper than a LUMO level of the first organic compound and a LUMO level of the second organic compound by 0.2 eV or more, and wherein a HOMO level of the organometallic complex is located between a HOMO level of the first organic compound and a HOMO level of the second organic compound. ### Claim 9 A light-emitting device comprising: a first electrode; a hole transporting layer over the first electrode; a light-emitting layer over the hole transporting layer; an electron transporting layer over the light-emitting layer; and a second electrode over the electron transporting layer, wherein the light-emitting layer includes a first organic compound having a hole-transporting property, a second organic compound having an electron transporting property, and an organometallic complex, wherein the organometallic complex is represented by a general formula (G1), wherein Ar represents an arylene group, R1 represents one of an alkyl group and an aryl group, R2 represents one of hydrogen, an alkyl group and an aryl group, R3 represents one of hydrogen and an alkyl group, M represents a central metal, and the central metal comprises an element belonging to one of Group 9 and Group 10, and wherein an amount of the second organic compound is equal to or higher than an amount of the first organic compound. ### Claim 10 (depends on 9) The light-emitting device according to claim 9, wherein the Ar is represented by a general formula (G2), and wherein R4 to R7 each represent one of hydrogen, an alkyl group, a halogen group, a haloalkyl group, an alkoxy group, and an alkoxycarbonyl group. ### Claim 11 (depends on 9) The light-emitting device according to claim 9, wherein the Ar is represented by a general formula (G2), wherein the R2 is represented by a general formula (G3), and wherein R4 to R12 each represent one of hydrogen, an alkyl group, a halogen group, a haloalkyl group, an alkoxy group, and an alkoxycarbonyl group. ### Claim 12 (depends on 9) The light-emitting device according to claim 9, wherein the central metal comprises one of iridium and platinum, the first organic compound comprises one of an aromatic amine compound and a carbazole derivative, and the second organic compound comprises one of a heteroaromatic compound and a metal complex. ### Claim 13 (depends on 9) The light-emitting device according to claim 9, wherein an amount of the organometallic complex in the light-emitting layer is greater than or equal to 1 percent by mass and less than or equal to 10 percent by mass. ### Claim 14 (depends on 9) The light-emitting device according to claim 9, wherein a mass ratio of the second organic compound to the first organic compound is 1 to 20 inclusive. ### Claim 15 (depends on 9) The light-emitting device according to claim 9, wherein a LUMO level of the organometallic complex is deeper than a LUMO level of the first organic compound and a LUMO level of the second organic compound by 0.2 eV or more, and wherein a HOMO level of the organometallic complex is located between a HOMO level of the first organic compound and a HOMO level of the second organic compound. ### Claim 16 A light-emitting device comprising: a first electrode; a hole transporting layer over the first electrode; a light-emitting layer over the hole transporting layer; an electron transporting layer over the light-emitting layer; and a second electrode over the electron transporting layer, wherein the light-emitting layer includes a first organic compound having a hole-transporting property, a second organic compound having an electron transporting property, and an organometallic complex, wherein the organometallic complex is represented by a general formula (G4), wherein Ar represents an arylene group, R1 represents one of an alkyl group and an aryl group, R2 represents one of hydrogen, an alkyl group and an aryl group, R3 represents one of hydrogen and an alkyl group, M represents a central metal, the central metal comprises an element belonging to one of Group 9 and Group 10, and L represents a monoanionic ligand, wherein when the central metal comprises an element belonging to Group 9, n is 2 and when the central metal comprises an element belonging to Group 10, n is 1, wherein an amount of the second organic compound is equal to or higher than an amount of the first organic compound. ### Claim 17 (depends on 16) The light-emitting device according to claim 16, wherein the Ar is represented by a general formula (G5), and wherein R4 to R7 each represent one of hydrogen, an alkyl group, a halogen group, a haloalkyl group, an alkoxy group, and an alkoxycarbonyl group. ### Claim 18 (depends on 16) The light-emitting device according to claim 16, wherein the Ar is represented by a general formula (G5), wherein the R2 is represented by a general formula (G6), and wherein R4 to R12 each represent one of hydrogen, an alkyl group, a halogen group, a haloalkyl group, an alkoxy group, and an alkoxycarbonyl group. ### Claim 19 (depends on 16) The light-emitting device according to claim 16, wherein the central metal comprises one of iridium and platinum, the first organic compound comprises one of an aromatic amine compound and a carbazole derivative, and the second organic compound comprises one of a heteroaromatic compound and a metal complex. ### Claim 20 (depends on 16) The light-emitting device according to claim 16, wherein an amount of the organometallic complex in the light-emitting layer is greater than or equal to 1 percent by mass and less than or equal to 10 percent by mass. ### Claim 21 (depends on 16) The light-emitting device according to claim 16, wherein a mass ratio of the second organic compound to the first organic compound is 1 to 20 inclusive. ### Claim 22 (depends on 16) The light-emitting device according to claim 16, wherein a LUMO level of the organometallic complex is deeper than a LUMO level of the first organic compound and a LUMO level of the second organic compound by 0.2 eV or more, and wherein a HOMO level of the organometallic complex is located between a HOMO level of the first organic compound and a HOMO level of the second organic compound.