# US 12,114,517 B2 · Light-emitting element and light-emitting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,517 B2 - Document ID: US12114517B2 - Status: Granted - Kind: B2 - Application number: 17/439,369 - Filed: 2019-03-22 - Published: 2022-05-19 - Granted: 2024-10-08 - Earliest claimed: 2019-03-22 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: Masanobu Mizusaki; Hiroshi Tsuchiya - Web page: https://patentgrep.com/patent/US12114517B2 ## CPC - H10K 50/11: characterised by the electroluminescent [EL] layers - 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} - H10H 20/822: Materials of the light-emitting regions - H10K 50/156: {comprising a multilayered structure} - H10K 50/166: {comprising a multilayered structure} - H10K 59/122: Pixel-defining structures or layers, e.g. banks - H10K 71/00: Manufacture or treatment specially adapted for the organic devices covered by this subclass - H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values - H10K 2101/40: Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract In a light-emitting element, an energy level difference between a second hole transport layer and the light-emitting layer on a side closer to the second hole transport layer is greater than an energy level difference between the light-emitting layer on the side closer to the second hole transport layer and a layer in contact with a side closer to a cathode electrode of the light-emitting layer on the side closer to the second hole transport layer in LUMO level, and an energy level difference between a first electron transport layer and the light-emitting layer on a side closer to the first electron transport layer is greater than an energy level difference between the light-emitting layer on the side closer to the first electron transport layer and a layer in contact with a side closer to an anode electrode of the light-emitting layer on the side closer to the first electron transport layer in HOMO level. ## Claims ### Claim 1 A light-emitting element comprising: an anode electrode; a cathode electrode; a first hole transport layer; a second hole transport layer; a light-emitting layer; a first electron transport layer; and a second electron transport layer, wherein the first hole transport layer, the second hole transport layer, the light-emitting layer, the first electron transport layer, and the second electron transport layer are provided between the anode electrode and the cathode electrode in order from a side closer to the anode electrode, a value of a lowest unoccupied molecular orbital (LUMO) level of the second hole transport layer is greater than a value of a LUMO level of the light-emitting layer, and a value of a LUMO level of the light-emitting layer is equal to or greater than a value of a LUMO level of the first electron transport layer, a value of a highest occupied molecular orbital (HOMO) level of the light-emitting layer is greater than a value of a HOMO level of the first electron transport layer, an energy level difference between the second hole transport layer and the light-emitting layer is greater than an energy level difference between the light-emitting layer and the first electron transport layer in a LUMO level, an energy level difference between the first electron transport layer and the light-emitting layer is greater than an energy level difference between the light-emitting layer and the second hole transport layer in a HOMO level, the light-emitting layer is a single layer, an energy level difference between the light-emitting layer and the first electron transport layer in the LUMO level is not less than 0.0 eV and not greater than 0.15 eV, and an energy level difference between the light-emitting layer and the second hole transport layer in the HOMO level is not less than 0.0 eV and not greater than 0.15 eV. ### Claim 2 (depends on 1) The light-emitting element according to claim 1, wherein a difference between the value of the LUMO level of the light-emitting layer and the value of the HOMO level of the light-emitting layer is greater than 2.7 eV and less than or equal to 3.1 eV. ### Claim 3 (depends on 1) The light-emitting element according to claim 1, wherein the light-emitting layer is configured to emit blue light. ### Claim 4 (depends on 1) The light-emitting element according to claim 1, wherein the light-emitting layer includes a first light-emitting layer of a hole transport type on a side closer to the second hole transport layer, and a second light-emitting layer of an electron transport type on a side closer to the first electron transport layer. ### Claim 5 (depends on 4) The light-emitting element according to claim 4, wherein an energy level difference between the first light-emitting layer and the second light-emitting layer in the LUMO level is greater than or equal to 0.25 eV, and an energy level difference between the first light-emitting layer and the second light-emitting layer in the HOMO level is greater than or equal to 0.25 eV. ### Claim 6 (depends on 5) The light-emitting element according to claim 5, wherein the energy level difference between the first light-emitting layer and the second light-emitting layer in the LUMO level is greater than or equal to 0.35 eV, and the energy level difference between the first light-emitting layer and the second light-emitting layer in the HOMO level is greater than or equal to 0.35 eV. ### Claim 7 (depends on 4) The light-emitting element according to claim 4, wherein both an energy level difference between the first electron transport layer and the second electron transport layer and an energy level difference between the second light-emitting layer and the first electron transport layer in the LUMO level are not less than 0.0 eV and not greater than 0.15 eV, and both an energy level difference between the first hole transport layer and the second hole transport layer and an energy level difference between the first light-emitting layer and the second hole transport layer in the HOMO level are not less than 0.0 eV and not greater than 0.15 eV. ### Claim 8 (depends on 4) The light-emitting element according to claim 4, wherein a difference between the value of the LUMO level of the second light-emitting layer and a value of a HOMO level of the first light-emitting layer is not less than 2.4 eV and not greater than 2.7 eV. ### Claim 9 (depends on 4) The light-emitting element according to claim 4, wherein the first light-emitting layer and the second light-emitting layer are configured to emit green light. ### Claim 10 (depends on 4) The light-emitting element according to claim 4, wherein the first light-emitting layer and the second light-emitting layer are configured to emit red light. ### Claim 11 (depends on 1) The light-emitting element according to claim 1, wherein a value of a LUMO level of the first hole transport layer is greater than the value of the LUMO level of the second hole transport layer, and the value of the LUMO level of the first electron transport layer is equal to or greater than a value of a LUMO level of the second electron transport layer, and a value of a HOMO level of the first hole transport layer is greater than or equal to a value of a HOMO level of the second hole transport layer, and the value of the HOMO level of the first electron transport layer is greater than a value of a HOMO level of the second electron transport layer. ### Claim 12 (depends on 11) The light-emitting element according to claim 11, wherein the energy level difference between the first electron transport layer and the second electron transport layer in the LUMO level is not less than 0.0 eV and not greater than 0.15 eV, and the energy level difference between the first hole transport layer and the second hole transport layer in the HOMO level is not less than 0.0 eV and not greater than 0.15 eV. ### Claim 13 (depends on 1) A light-emitting device comprising at least one of the light-emitting element according to claim 1. ### Claim 14 A light-emitting element comprising: an anode electrode; a cathode electrode; a first hole transport layer; a second hole transport layer; a light-emitting layer; a first electron transport layer; and a second electron transport layer, wherein the first hole transport layer, the second hole transport layer, the light-emitting layer, the first electron transport layer, and the second electron transport layer are provided between the anode electrode and the cathode electrode in order from a side closer to the anode electrode, a value of a lowest unoccupied molecular orbital (LUMO) level of the second hole transport layer is greater than a value of a LUMO level of a first light-emitting layer on a side closer to the second hole transport layer, and a value of a LUMO level of a second light-emitting layer on a side closer to the first electron transport layer is equal to or greater than a value of a LUMO level of the first electron transport layer, a value of a highest occupied molecular orbital (HOMO) level of the second light-emitting layer on the side closer to the first electron transport layer is greater than a value of a HOMO level of the first electron transport layer, an energy level difference between the second hole transport layer and the first light-emitting layer on the side closer to the second hole transport layer is greater than an energy level difference between the first light-emitting layer on the side closer to the second hole transport layer and the second light-emitting layer on the side closer to the first electron transport layer in a LUMO level, an energy level difference between the first electron transport layer and the second light-emitting layer on the side closer to the first electron transport layer is greater than an energy level difference between the second light-emitting layer on the sider closer the first electron transport layer and the first light-emitting layer on the side closer to the second hole transport layer in a HOMO level, the first light-emitting layer on the side closer to the second hole transport layer and the second light-emitting layer on the side closer to the first electron transport layer are the same, an energy level difference between the light-emitting layer and the first electron transport layer in the LUMO level is not less than 0.0 eV and not greater than 0.15 eV, an energy level difference between the light-emitting layer and the second hole transport layer in the HOMO level is not less than 0.0 eV and not greater than 0.15 eV, and the light-emitting layer is configured to emit red light.