# US 2008/0187748 A1 · Organic electroluminescence device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0187748 A1 - Document ID: US20080187748A1 - Status: Published application - Kind: A1 - Application number: 12/024,892 - Filed: 2008-02-01 - Published: 2008-08-07 - Earliest claimed: 2007-02-07 - Inventors: Masayuki MISHIMA - Web page: https://patentgrep.com/patent/US20080187748A1 ## CPC - H10K 85/60: Organic compounds having low molecular weight (H10K85/10 - H10K85/50 take precedence) - H10K 50/11: characterised by the electroluminescent [EL] layers - H10K 85/324: {comprising aluminium, e.g. Alq3} - H10K 85/342: {comprising iridium} - H10K 85/346: {comprising platinum} - H10K 85/633: {comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom} - H10K 2101/10: Triplet emission - H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values - H10K 2102/103: {comprising indium oxides, e.g. ITO} - Y10T 428/265: 1 mil or less - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An organic electroluminescence device including a light-emitting layer which contains at least a first light-emitting material, a second light-emitting material, and an electrically inactive material having an energy difference between a highest occupied molecular orbital and a lowest unoccupied molecular orbital of 4.0 eV or larger, wherein the first light-emitting material is an electron-transporting material, the second light-emitting material is a hole-transporting material, and the light-emitting layer has a thickness within a range of from 0.5 nm to 20 nm. ## Claims ### Claim 1 An organic electroluminescence device comprising, between a pair of electrodes opposed to each other, an organic compound layer including at least a light-emitting layer, wherein the light-emitting layer contains at least a first light-emitting material and a second light-emitting material, and an electrically inactive material having an energy difference (Eg) between a highest occupied molecular orbital and a lowest unoccupied molecular orbital of 4.0 eV or larger, wherein: the first light-emitting material is an electron-transporting light-emitting material, the second light-emitting material is a hole-transporting light-emitting material, and the light-emitting layer has a thickness within a range of from 0.5 nm to 20 nm. ### Claim 2 (depends on 1) The organic electroluminescence device according to claim 1, wherein: an electron affinity (Ea1) of the first light-emitting material is larger than an electron affinity (Ea2) of the second light-emitting material, and an ionization potential (Ip1) of the first light-emitting material is larger than an ionization potential (Ip2) of the second light-emitting material. ### Claim 3 (depends on 1) The organic electroluminescence device according to claim 1, wherein the first light-emitting material is a platinum complex. ### Claim 4 (depends on 1) The organic electroluminescence device according to claim 1, wherein the second light-emitting material is an iridium complex. ### Claim 5 (depends on 1) The organic electroluminescence device according to claim 1, wherein the first light-emitting material is a platinum complex, and the second light-emitting material is an iridium complex. ### Claim 6 (depends on 1) The organic electroluminescence device according to claim 1, wherein the light-emitting layer has a thickness within a range of from 1 nm to 10 nm. ### Claim 7 (depends on 1) The organic electroluminescence device according to claim 1, wherein a proportion of the light-emitting materials with respect to a total amount of the light-emitting materials and the electrically inactive material in the light-emitting layer is from 5% to 40% by weight. ### Claim 8 (depends on 1) The organic electroluminescence device according to claim 1, wherein the electrically inactive material is an organic compound having an ionization potential (Ip) larger than that of the light-emitting material. ### Claim 9 (depends on 1) The organic electroluminescence device according to claim 1, wherein the electrically inactive material is an organic compound having an electron affinity (Ea) smaller than that of the light-emitting material. ### Claim 10 (depends on 1) The organic electroluminescence device according to claim 1, wherein the electrically inactive material is an aromatic hydrocarbon compound. ### Claim 11 (depends on 10) The organic electroluminescence device according to claim 10, wherein the aromatic hydrocarbon compound is a compound represented by the following formula (1): L-(Ar)m Formula (1) wherein, in formula (1), Ar represents a group represented by the following formula (2); L represents a benzene skeleton having a valency of 3 or more; and m represents an integer of 3 or more: wherein, in formula (2), R1 represents a substituent, with a proviso that, if plural R1s are present, R1s may be the same or different from each other; and n1 represents an integer from 0 to 9. ### Claim 12 (depends on 10) The organic electroluminescence device according to claim 10, wherein the aromatic hydrocarbon compound is a compound represented by the following formula (3): wherein, in formula (3), R2 represents a substituent, with a proviso that, if plural R2s are present, R2s may be the same or different from each other; and n2 represents an integer from 0 to 20. ### Claim 13 (depends on 1) The organic electroluminescence device according to claim 1, wherein the electrically inactive material is an insulating inorganic compound. ### Claim 14 (depends on 1) The organic electroluminescence device according to claim 1, wherein the organic compound layer includes, from an anode side, at least either one of a hole injection layer and a hole transport layer, the light-emitting layer, and at least either one of an electron transport layer and an electron injection layer, and at least either one of the hole injection layer and the hole transport layer contains an electron-accepting material. ### Claim 15 (depends on 1) The organic electroluminescence device according to claim 1, wherein the organic compound layer includes, from an anode side, at least either one of a hole injection layer and a hole transport layer, the light-emitting layer, and at least either one of an electron transport layer and an electron injection layer, and at least either one of the electron transport layer and the electron injection layer contains an electron-donating material.