# US 2014/0151678 A1 · Organic light-emitting element, light source device and method of manufacturing organic light-emitting element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151678 A1 - Document ID: US20140151678A1 - Status: Published application - Kind: A1 - Application number: 14/233,628 - Filed: 2012-07-03 - Published: 2014-06-05 - Earliest claimed: 2011-07-19 - Assignees: Hitachi, Ltd. - Inventors: Hirotaka Sakuma; Sukekazu Aratani; Shunichiro Nobuki; Shingo Ishihara - Web page: https://patentgrep.com/patent/US20140151678A1 ## CPC - H10K 71/191: {characterised by provisions for the orientation or alignment of the layer to be deposited} - H10K 50/856: comprising reflective means - H10K 50/818: Reflective anodes, e.g. ITO combined with thick metallic layers - H10K 50/858: comprising refractive means, e.g. lenses - H10K 85/346: {comprising platinum} - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract In order to achieve the increased efficiency of an organic light-emitting element, there is a need to reduce the influence of non-radiative recombination of electron-hole pairs except for surface plasmon polariton excitation, to convert most of exciton energy into visible light, and to tremendously improve the luminous efficiency of the organic light-emitting element. An organic light-emitting element according to the present invention includes a reflective electrode, a transparent electrode, and a light-emitting layer placed between the reflective electrode and the transparent electrode, and the organic light-emitting element is configured so that the light-emitting layer contains a host and a first dopant, and for the first dopant, one of the vertical component and horizontal component of the average value for transition dipole moments with respect to a substrate surface is larger than the other of the components. ## Claims ### Claim 1 An organic light-emitting element comprising: a lower electrode and an upper electrode, one of the electrode serving as a reflective electrode, and the other thereof serving as a transparent electrode; and a light-emitting layer placed between the lower electrode and the upper electrode, the light-emitting layer containing a host and a first dopant, wherein the first dopant contains a first functional group, for the first dopant, one of a vertical component and a horizontal component of an average value for transition dipole moments with respect to a substrate surface is larger than the other of the components, and the concentration of the first dopant is higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions. ### Claim 2 (depends on 1) The organic light-emitting element according to claim 1, wherein the dopant contained in the light-emitting layer has planar molecules, one of a vertical component and a horizontal component of an average value for the planar molecules with respect to the substrate surface is larger than the other of the components. ### Claim 3 (depends on 1) The organic light-emitting element according to claim 1, wherein the dopant contained in the light-emitting layer has rod-like molecules, one of a vertical component and a horizontal component of an average value for long axes of the rod-like molecules with respect to the substrate surface is larger than the other of the components. ### Claim 4 (depends on 1) The organic light-emitting element according to claim 1, wherein for the first dopant, one of the vertical component and horizontal component of the average value for transition dipole moments with respect to the substrate surface is 60% or more. ### Claim 5 An organic light-emitting element comprising: a reflective electrode; a transparent electrode; and a light-emitting layer placed between the reflective electrode and the transparent electrode, wherein the light-emitting layer contains a host and a first dopant, for the first dopant, a vertical component of an average value for transition dipole moments with respect to the substrate surface is larger than a horizontal component thereof, and the reflective electrode has a concave-convex structure on a side closer to the light-emitting layer. ### Claim 6 (depends on 5) The organic light-emitting element according to claim 5, wherein the first dopant contains a first functional group, and the concentration of the first dopant is higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions. ### Claim 7 (depends on 5) The organic light-emitting element according to claim 5, wherein the light-emitting layer contains a second dopant, the second dopant has a luminescent color different from that of the first dopant, and for the second dopant, a vertical component of an average value for transition dipole moments with respect to the substrate surface is larger than a horizontal component thereof. ### Claim 8 (depends on 7) The organic light-emitting element according to claim 7, wherein the light-emitting layer contains a third dopant, the third dopant has a luminescent color different from those of the first dopant and second dopant, and for the third dopant, a vertical component of an average value for transition dipole moments with respect to the substrate surface is larger than a horizontal component thereof. ### Claim 9 (depends on 5) The organic light-emitting element according to claim 5, wherein for the first dopant, the vertical component of the average value for transition dipole moments with respect to the substrate surface is 60% or more. ### Claim 10 (depends on 5) The organic light-emitting element according to claim 5, wherein any one of the dopants contained in the light-emitting layer has planar molecules, and a vertical component of an average value for the planar molecules with respect to the substrate surface is larger than a horizontal component thereof. ### Claim 11 (depends on 5) The organic light-emitting element according to claim 5, wherein any one of the dopants contained in the light-emitting layer has rod-like molecules, and a vertical component of an average value for long axes of the rod-like molecules with respect to the substrate surface is larger than a horizontal component thereof. ### Claim 12 (depends on 5) The organic light-emitting element according to claim 5, wherein the concave-convex structure contains Ag, Au, Cu, or Al as its main constituent. ### Claim 13 (depends on 5) The organic light-emitting element according to claim 5, wherein the concave-convex structure has a concave-convex height, width, and pitch smaller than an emission wavelength. ### Claim 14 (depends on 13) The organic light-emitting element according to claim 13, wherein the concave-convex height falls within the range of 40 to 120 nm. ### Claim 15 (depends on 5) The organic light-emitting element according to claim 5, wherein the organic light-emitting element has a light extraction layer on the side opposite to the location of the reflective electrode from the transparent electrode. ### Claim 16 An organic light-emitting element comprising: an upper electrode; a lower electrode; and a light-emitting layer placed between the upper electrode and the lower electrode, wherein the light-emitting layer contains a host and a first dopant, the first dopant contains a first functional group, the concentration of the first dopant is higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions, and for the first dopant, a horizontal component of an average value for transition dipole moments with respect to a substrate surface is larger than a vertical component thereof. ### Claim 17 (depends on 16) The organic light-emitting element according to claim 16, wherein the light-emitting layer contains a second dopant, the second dopant has a luminescent color different from that of the first dopant, the second dopant contains a second functional group, the concentration of the second dopant is higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions, and for the second dopant, a horizontal component of an average value for transition dipole moments with respect to the substrate surface is larger than a vertical component thereof. ### Claim 18 (depends on 17) The organic light-emitting element according to claim 17, wherein the light-emitting layer contains a third dopant, the third dopant has a luminescent color different from those of the first dopant and the second dopant, the third dopant contains a third functional group, the concentration of the third dopant is higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions, and for the third dopant, a horizontal component of an average value for transition dipole moments with respect to the substrate surface is larger than a vertical component thereof. ### Claim 19 (depends on 16) The organic light-emitting element according to claim 16, wherein for the first dopant, the horizontal component of the average value for transition dipole moments with respect to the substrate surface is 60% or more. ### Claim 20 (depends on 16) The organic light-emitting element according to claim 16, wherein any one of the dopants contained in the light-emitting layer has planar molecules, and a horizontal component of an average value for the planar molecules with respect to the substrate surface is larger than a vertical component thereof. ### Claim 21 (depends on 16) The organic light-emitting element according to claim 16, wherein any one of the dopants contained in the light-emitting layer has rod-like molecules, and a horizontal component of an average value for long axes of the rod-like molecules with respect to the substrate surface is larger than a vertical component thereof. ### Claim 22 (depends on 1) The organic light-emitting element according to claim 1, wherein the first functional group is one or more selected from a fluoroalkyl group, a perfluoroalkyl group, an alkyl group (the number of C is 10 or more), a perfluoropolyether group, and a siloxy group, and —OH, —SH, —COOH, —SO3H, I, Br, Cl, F, SCN, CN, NH2, NO2, and a bipyridyl group, a phenylamino group, an oxazole group, a carbazole group, and a hydrazone moiety. ### Claim 23 (depends on 1) The organic light-emitting element according to claim 1, wherein the first dopant is a metal complex including a four-coordinated central metal. ### Claim 24 (depends on 23) The organic light-emitting element according to claim 23, wherein the first dopant is represented by the general formula (1). (In the formula, N-L1-X1 and X2-L2-X3 each represent a bidentate ligand, X1, X2, and X3 each independently represent a carbon atom, an oxygen atom, or a nitrogen atom, L1 and L2 represent groups of atoms that respectively form bidentate ligands along with N and X1 and X2 and X3, and a central metal M represents Ni, Pd, Pt, Au, Ag, Rh, or Ir) ### Claim 25 (depends on 1) A light source device comprising the organic light-emitting element according to claim 1. ### Claim 26 A method of manufacturing an organic light-emitting element comprising a reflective electrode, a transparent electrode, and a light-emitting layer placed between the reflective electrode and the transparent electrode, wherein the light-emitting layer contains a host and a first dopant, for the first dopant, a vertical component of an average value for transition dipole moments with respect to a substrate surface is larger than a horizontal component thereof, the light-emitting layer is prepared by coating, and a concave-convex structure is formed on a side of the reflective electrode closer to the light-emitting layer. ### Claim 27 A light source device comprising a first organic light-emitting element and a second organic light-emitting element, wherein the first organic light-emitting element and the second organic light-emitting element each comprises a reflective electrode, a transparent electrode, and a light-emitting layer placed between the reflective electrode and the transparent electrode, the light-emitting layer of the first organic light-emitting element contains a first host and a first dopant, the light-emitting layer of the second organic light-emitting element contains a second host, a second dopant, and a third dopant. for the first dopant, the second dopant, and the third dopant, vertical components of average values for transition dipole moments with respect to a substrate surface is larger than horizontal components thereof, and the light source device comprises a concave-convex structure on a side of the reflective electrode closer to the light-emitting layer. ### Claim 28 A method of manufacturing an organic light-emitting element comprising an upper electrode, a lower electrode, and a light-emitting layer placed between the upper electrode and the lower electrode, wherein the light-emitting layer contains a host and a first dopant, the first dopant contains a first functional group, the concentration of the first dopant is higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions, for the first dopant, a horizontal component of an average value for transition dipole moments with respect to a substrate surface is larger than a vertical component thereof, and the light-emitting layer is prepared by coating. ### Claim 29 A light source device comprising a first organic light-emitting element and a second organic light-emitting element, wherein the first organic light-emitting element and the second organic light-emitting element each comprises an upper electrode, a lower electrode, and a light-emitting layer placed between the upper electrode and the lower electrode, the light-emitting layer of the first organic light-emitting element contains a host and a first dopant, the light-emitting layer of the second organic light-emitting element contains a host, a second dopant, and a third dopant the first dopant contains a first functional group, the second dopant contains a second functional group, the third dopant contains a third functional group, the concentrations of the first dopant, second dopant, and third dopant are higher in either one of: a region of the light-emitting layer with the upper electrode closer thereto; and a region thereof with the lower electrode closer thereto, than in the other of the regions, and for the first dopant, the second dopant, and the third dopant, horizontal components of average values for transition dipole moments with respect to a substrate surface is larger than vertical components thereof. ### Claim 30 (depends on 27) The light source device according to claim 27, wherein the first dopant is a blue dopant, and one of the second dopant and the third dopant is a red dopant, whereas the other thereof is a green dopant.