# US 2017/0284609 A1 · Light-emitting device having photoluminescent layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0284609 A1 - Document ID: US20170284609A1 - Status: Published application - Kind: A1 - Application number: 15/446,453 - Filed: 2017-03-01 - Published: 2017-10-05 - Earliest claimed: 2016-03-30 - Assignees: Panasonic Intellectual Property Management Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: TAKU HIRASAWA; YASUHISA INADA; AKIRA HASHIYA - Web page: https://patentgrep.com/patent/US20170284609A1 ## CPC - F21K 9/64: using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer - F21V 9/14: for producing polarised light - F21V 9/30: Elements containing photoluminescent material distinct from or spaced from the light source (shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40) - H10H 20/8514: {characterised by their shape, e.g. plate or foil} - H10H 20/8515: {not being in contact with the bodies} - H10H 20/8516: {having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer or wavelength conversion layer with a concentration gradient} - H10H 20/853: characterised by their shape - H10H 20/855: Optical field-shaping means, e.g. lenses - F21Y 2115/10: Light-emitting diodes [LED] - F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## Abstract A light-emitting device comprises a layered structure between a first layer and a second layer. The first first layer has a refractive index n1 for first light having a wavelength λa in air. The second layer has a refractive index n2 for the first light. The layered structure comprises: a photoluminescent layer having a first surface facing the first layer and a second surface facing the second layer; and a surface structure disposed on at least one selected from the group consisting of the first surface and the second surface of the photoluminescent layer. The refractive index n1 and the refractive index n2 are lower than a refractive index nwav-a of the photoluminescent layer for the first light. The layered structure has an effective thickness to more strongly emit TE polarized light than TM polarized light. ## Claims ### Claim 1 A light-emitting device comprising a layered structure between a first layer and a second layer, the first first layer having a refractive index n1 for first light having a wavelength λa in air, the second layer having a refractive index n2 for the first light, the layered structure comprising: a photoluminescent layer having a first surface facing the first layer and a second surface facing the second layer; and a surface structure disposed on at least one selected from the group consisting of the first surface and the second surface of the photoluminescent layer, the surface structure having projections and recesses, wherein the photoluminescent layer emits the first light upon receiving excitation light, the refractive index n1 and the refractive index n2 are lower than a refractive index nwav-a of the photoluminescent layer for the first light and satisfy a relationship n1>n2, and the layered structure has an effective thickness to more strongly emit TE polarized light than TM polarized light. ### Claim 2 (depends on 1) The light-emitting device according to claim 1, wherein at least one selected from the group consisting of a portion of the first layer and a portion of the second layer is disposed in the recesses of the surface structure, and an effective thickness teff satisfies the following relational expressions (1) and (2), wherein twav denotes a thickness of the photoluminescent layer, h denotes a thickness of the surface structure, np denotes a refractive index of the surface structure for the first light, Rv denotes a ratio of a volume of the recesses to a volume of the projections and the recesses, and m is an integer. λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] < t eff < λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n wav - a 2 n   2 2  n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] ( 1 )  t eff = t wav + ( 1 - R v ) · h · n p n wav - a ( 2 ) ### Claim 3 (depends on 1) The light-emitting device according to claim 1, wherein the photoluminescent layer includes discrete belt-like portions, the surface structure is disposed on the belt-like portions, at least one selected from the group consisting of a portion of the first layer and a portion of the second layer is disposed in the recesses of the surface structure, and an effective thickness teff satisfies the following relational expressions (3) and (4), wherein twav denotes a thickness of the belt-like portions, h denotes a thickness of the surface structure, np denotes a refractive index of the surface structure for the first light, Rv denotes a ratio of a volume of the recesses to a volume of the projections and the recesses, and m is an integer. λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] < t eff < λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n wav - a 2 n   2 2  n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] ( 3 )  t eff = t wav + ( 1 - R v ) · h · n p n wav - a ( 4 ) ### Claim 4 A light-emitting device comprising a layered structure between a first layer and a second layer, the first first layer having a refractive index n1 for first light having a wavelength λa in air, the second layer having a refractive index n2 for the first light, the layered structure comprising: a light guiding layer having a first surface facing the first layer and a second surface facing the second layer; and a surface structure disposed on at least one selected from the group consisting of the first surface and the second surface of the light guiding layer, the surface structure having projections and recesses, wherein the light guiding layer includes a photoluminescent layer that emits the first light upon receiving excitation light and that has a refractive index nwav-a for the first light, and an intermediate layer disposed between the surface structure and the photoluminescent layer, the intermediate layer having a refractive index nm for the first light, the refractive index n1 and the refractive index n2 are lower than a refractive index of the light guiding layer for the first light and satisfy a relationship n1>n2, and the layered structure has an effective thickness to more strongly emit TE polarized light than TM polarized light. ### Claim 5 (depends on 4) The light-emitting device according to claim 4, wherein at least one selected from the group consisting of a portion of the first layer and a portion of the second layer is disposed in the recesses of the surface structure, and an effective thickness teff satisfies the following relational expressions (5) and (6), wherein twav denotes a thickness of the photoluminescent layer, h denotes a thickness of the surface structure, tm denotes a thickness of the intermediate layer, np denotes a refractive index of the surface structure for the first light, Rv denotes a ratio of a volume of the recesses to a volume of the projections and the recesses, and m is an integer. λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] < t eff < λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n wav - a 2 n   2 2  n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] ( 5 )  t eff = t wav + ( 1 - R v ) · h · n p n wav - a + t m · n m n wav - a ( 6 ) ### Claim 6 (depends on 4) The light-emitting device according to claim 4, wherein the photoluminescent layer includes discrete belt-like portions, the surface structure is disposed on the belt-like portions, at least one selected from the group consisting of a portion of the first layer and a portion of the second layer is disposed in the recesses of the surface structure, and the effective thickness teff satisfies the following relational expressions (7) and (8), wherein twav denotes a thickness of the belt-like portions, h denotes a thickness of the surface structure, tm denotes a thickness of the intermediate layer, np denotes a refractive index of the surface structure for the first light, Rv denotes a ratio of a volume of the recesses to a volume of the projections and the recesses, and m is an integer. λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] < t eff < λ a 2   π  n wav - a 2 - n   1 2 [ tan - 1 ( n wav - a 2 n   2 2  n   1 2 - n   2 2 n wav - a 2 - n   1 2 ) + m   π ] ( 7 )  t eff = t wav + ( 1 - R v ) · h · n p n wav - a + t m · n m n wav - a ( 8 ) ### Claim 7 (depends on 3) The light-emitting device according to claim 3, wherein the belt-like portions are separately arranged in a first direction, and the projections and the recesses extend in the first direction. ### Claim 8 (depends on 7) The light-emitting device according to claim 7, wherein the projections and the recesses are arranged perpendicularly to the first direction. ### Claim 9 (depends on 7) The light-emitting device according to claim 7, wherein a length of the belt-like portions in the first direction is not more than four times a distance Dint between two adjacent projections or between two adjacent recesses. ### Claim 10 (depends on 7) The light-emitting device according to claim 7, wherein a length of the belt-like portions in the first direction is 2 μm or less. ### Claim 11 (depends on 1) The light-emitting device according to claim 1, wherein the first layer or the second layer is a substrate that supports the photoluminescent layer. ### Claim 12 (depends on 11) The light-emitting device according to claim 11, wherein the photoluminescent layer is in direct contact with the substrate. ### Claim 13 (depends on 1) The light-emitting device according to claim 1, wherein the first layer or the second layer is air. ### Claim 14 (depends on 1) The light-emitting device according to claim 1, wherein a distance Dint between two adjacent projections or between two adjacent recesses in the surface structure satisfies a relationship (λa/nwav-a)