# US 5,505,986 A · Multi-source reactive deposition process for the preparation of blue light emitting phosphor layers for AC TFEL devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,505,986 A - Document ID: US5505986A - Status: Granted - Kind: A - Application number: 08/195,999 - Filed: 1994-02-14 - Granted: 1996-04-09 - Earliest claimed: 1994-02-14 - Assignees: Planar Systems, Inc. - Inventors: Karl-Otto Velthaus; Reiner H. Mauch; T. Achim Oberacker; Hans-Werner Schock; Sey-Shing Sun; Randall C. Wentross; Richard T. Tuenge - Web page: https://patentgrep.com/patent/US5505986A ## CPC - C23C 14/24: Vacuum evaporation - C09K 11/7718: {with alkaline earth metals} - C09K 11/7731: {with alkaline earth metals} - C09K 11/886: {with rare earth metals} - C23C 14/0623: {Sulfides, selenides or tellurides} - C23C 14/541: {Heating or cooling of the substrates} - H05B 33/10: Apparatus or processes specially adapted to the manufacture of electroluminescent light sources - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A multi-source reactive deposition process for preparing a phosphor layer for an AC TFEL device having the chemical formula M.sup.II M.sup.III.sub.2 X.sub.4 :RE, where M.sup.II is a group II metal taken from the group magnesium, calcium, strontium and barium, M.sup.III is a group III metal taken from the group aluminum, gallium and indium, X is taken from the group sulfur and selenium, and RE comprises a rare earth activator dopant taken from the group cerium and europium is disclosed. The phosphor film is formed in crystalline form on a substrate heated to a temperature between 400.degree. and 800.degree. C. by depositing more than one deposition source chemical where at least one of the deposition source chemicals of the group II metal or the group III metal is a compound. ## Claims ### Claim 1 A process for preparing a phosphor layer for an AC TFEL device comprising a transparent substrate, said phosphor layer having the chemical formula: M.sup.II M.sup.III.sub.2 X.sub.4 :RE where M.sup.II is a group II metal taken from the group magnesium, calcium, strontium and barium; M.sup.III is a group III metal taken from the group aluminum, gallium and indium; X is taken from the group selenium and sulfur; and RE comprises a rare earth activator dopant taken from the group cerium and europium, said process comprising the steps of heating said substrate to a temperature between 400.degree. and 800.degree. C. and forming said phosphor layer in crystalline form on said heated substrate by depositing from vapor more than one deposition source chemical, wherein at least one of said deposition source chemicals of said group II metal or said group III metal is a compound, said deposition source chemicals comprising all of the elements of said phosphor layer. ### Claim 2 (depends on 1) The process of claim 1 wherein said deposition source chemical of said M.sup.II is M.sup.II X. ### Claim 3 (depends on 1) The process of claim 1 wherein said deposition source chemical of said M.sup.III is M.sup.III.sub.2 X.sub.3. ### Claim 4 (depends on 2, 3) The process of claim 2 or 3 wherein an effusion cell is used for coevaporation of each said deposition source chemical. ### Claim 5 (depends on 4) The process of claim 4 wherein each said effusion cell is a Knudsen cell. ### Claim 6 (depends on 4) The process of claim 4 wherein each said Knudsen cell defines an orifice and includes a shutter for selectively opening and closing said orifice, each said Knudsen cell is heated to a deposition source chemical vaporizing temperature and thereafter said shutter is opened for a vapor deposition time. ### Claim 7 A process for preparing a phosphor layer for an AC TFEL device comprising a transparent substrate, said phosphor layer having the chemical formula: M.sup.II M.sup.III.sub.2 X.sub.4 :RE where M.sup.II is a group II metal taken from the group magnesium, calcium, strontium and barium; M.sup.III is a group III metal taken from the group aluminum, gallium and indium; X is taken from the group selenium and sulfur; and RE comprises a rare earth activator dopant taken from the group cerium and europium, said process comprising the steps of: (a) placing each one of a plurality of deposition source chemicals comprising all of the elements of said phosphor layer in a respective effusion source having a selectively openable and closable shutter under an inert gas atmosphere and closing said shutter, wherein at least one of said deposition source chemicals of said group II metal or said group III metal is a compound; (b) thereafter placing said substrate and each said effusion source into a vacuum chamber and evacuating said vacuum chamber; (c) thereafter heating said substrate and each said effusion source to a respective elevated temperature to form a heated substrate and a chemical vapor in each said effusion source; (d) thereafter opening the shutter of each said effusion source for a vapor deposition time to allow said chemical vapor to form a phosphor layer on said heated substrate, and after said vapor deposition time, closing said shutter; and (e) thereafter cooling said substrate and venting said chamber to atmospheric pressure.