# US 9,520,521 B2 · Optically active coating for improving the yield of photosolar conversion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,521 B2 - Document ID: US9520521B2 - Status: Granted - Kind: B2 - Application number: 14/415,053 - Filed: 2013-07-16 - Published: 2015-09-24 - Granted: 2016-12-13 - Earliest claimed: 2012-07-16 - Assignees: Laboratoire De Physique Du Rayonnement Et De La LumièRe; Cascade Corporation - Applicants: Laboratoire De Physique Du Rayonnement Et De La LumièRe; Cascade - Inventors: Marc Schiffmann; François Le Poull; Philippe Gravisse - Web page: https://patentgrep.com/patent/US9520521B2 ## CPC - H10F 77/45: Wavelength conversion means, e.g. by using luminescent material, fluorescent concentrators or up-conversion arrangements - C09D 131/04: Homopolymers or copolymers of vinyl acetate - C09D 133/12: Homopolymers or copolymers of methyl methacrylate - H10F 77/496: {Luminescent members, e.g. fluorescent sheets (wavelength conversion means for photovoltaic cells H10F77/45)} - Y02E 10/52: PV systems with concentrators - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The invention relates to optically active coatings for improving the yield of photosolar conversion, consisting of a transparent matrix containing a plurality of optically active constituents absorbing the light energy in a first absorption wavelength lambdaA1 and reemitting the energy in a second wavelength lambdaR1 different from lambdaA1, said optically active constituents being selected such that the reemission wavelength lamdaR1 of at least one type of constituent corresponds to the absorption wavelength lambdaA2 of at least one second type of constituent, characterised in that the C2/C1 ratio of concentration C1 of the optically active constituents of a first type in relation to the concentration C2 of the optically active constituents of said second type is between 0.13 and 0.26; Ci designating the concentration in moles per liter of the constituent i in relation to the doped matrix. ## Claims ### Claim 1 An optically active coating for improving a yield of photosolar conversion, comprising: a transparent matrix including a plurality of optically active components absorbing light energy in a first absorption wavelength lambdaA1 and re-emitting the energy in a second wavelength lambdaR1 which is different from lambdaA1; the optically active components being selected such that the re-emission wavelength lambdaR1 of at least one type of component corresponds to the absorption wavelength lambdaR2 of at least one second type of component, a C2/C1 ratio of concentration C1 of the optically active components of the first type in relation to the concentration C2 of the optically active components of the second type is comprised between 0.13 and 0.26, Ci designating the concentration in moles per liter of the component i in relation to a doped matrix; and optically active molecules included in a micronised and/or powdered matrix of light-cascade doped PMMA, and then mixed into EVA granules. ### Claim 2 (depends on 1) The optically active coating according to claim 1, wherein the C2/C1 ratio of concentration C1 of the optically active components of the first type in relation to the concentration C2 of the optically active components of the second type is comprised between 0.13 and 0.26, Ci designating the concentration in moles per liter of the component i in relation to the doped matrix, the matrix is made up of an organic material selected among an ethylene vinyl acetate film, a polyvinyl chloride film and a film made up of a copolymer including 80% to 90% of low-density polyethylene and 10% to 20% of ethylene vinyl acetate. ### Claim 3 (depends on 1) The optically active coating according to claim 1, further comprising N types of Stokes components referred to by an abbreviation OACStokes wherein the re-emission wavelength is longer than the absorption wavelength, wherein N is equal to 3 or 5, the concentration Cn of the level-N components being also comprised between 0.4N and 0.6N, the matrix also containing an anti-Stokes component referred to by an abbreviation OACanti-Stokes, and wherein the re-emission wavelength is shorter than the absorption wavelength. ### Claim 4 (depends on 1) The optically active coating according to claim 1, wherein the type of level-N optically active components has a re-emission wavelength in which the peak is located between 945 nanometres and 980 nanometres. ### Claim 5 (depends on 1) The optically active coating improving the photosolar yield according to claim 1, wherein the matrix includes a film of ethylene vinyl acetate or polymethyl methacrylate. ### Claim 6 (depends on 1) The optically active coating improving the photosolar yield according to claim 1, wherein the matrix includes a methyl methacrylate resin or silicone. ### Claim 7 (depends on 1) The optically active coating improving the photosolar yield according to claim 1, the matrix includes a film of polyvinyl chloride or by a film made up of a copolymer including 80% to 90% low-density polyethylene and 10% to 20% ethylene vinyl acetate. ### Claim 8 (depends on 1) The optically active coating according to claim 1, further comprising OACanti-Stokes components wherein the re-emission wavelength, comprised between 550 and 800 nanometres, is shorter than the absorption wavelength, comprised between 1000 and 1500 nanometres. ### Claim 9 (depends on 1) The optically active coating according to claim 1, further comprising a reflective rear surface, the photovoltaic element being encapsulated in a matrix optically doped with a light cascade such as to form the coating. ### Claim 10 (depends on 1) The optically active coating according to claim 1, further comprising a plurality of photovoltaic elements forming a matrix with an expansion of 0.25 to 0.75, and areas between the photovoltaic elements being transparent. ### Claim 11 (depends on 9) The optically active coating according to claim 9, wherein the matrix encapsulating the photovoltaic elements includes persistent compounds which make it possible to release light in a lack of solar exposure. ### Claim 12 (depends on 1) The optically active coating according to claim 1, further comprising a film and/or an encapsulation plate pair including light cascades with OAMs arranged on a front surface, and mixed OAM and OAC LCs arranged on a rear surface. ### Claim 13 (depends on 1) Agricultural film manufactured according to claim 1, wherein the acgricultural films of different qualities and/or various thicknesses are co-extruded simultaneously by a same machine. ### Claim 14 (depends on 1) The optically active coating according to claim 1, wherein the concentration is a function of a thickness of the doped matrix. ### Claim 15 (depends on 1) The optically active coating according to claim 1, wherein the concentration is a function of molecular weight which is a function of a number of polycyclic rings.