Sulfur Containing Patents (Class 252/301.6S)
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Preparation of stable, bright luminescent nanoparticles having compositionally engineered properties
Patent number: 7695642Abstract: A method is provided for preparing luminescent semiconductor nanoparticles composed of a first component X, a second component A, and a third component B, wherein X, A, and B are different, by combining B with X and A in an amount such that the molar ratio B:(A+B) is in the range of approximately 0.001 to 0.20 and the molar ratio X:(A+B) is in the range of approximately 0.5:1.0 to 2:1. The characteristics of the thus-prepared nanoparticles can be substantially similar to those of nanoparticles containing only X and B while maintaining many useful properties characteristic of nanoparticles containing only X and A. The nanoparticles so prepared can additionally exhibit emergent properties such as a peak emission energy less than that characteristic of a particle composed of XA or XB alone; this method is particularly applicable to the preparation of stable, bright nanoparticles that emit in the red to infrared regions of the electromagnetic spectrum.Type: GrantFiled: December 13, 2004Date of Patent: April 13, 2010Assignee: Life Technologies CorporationInventors: Marc D. Schrier, Donald A. Zehnder, Joseph A. Treadway, Joseph A. Bartel -
Publication number: 20100044636Abstract: A semiconductor nanocrystal including a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light with an improved photoluminescence quantum efficiency. Also disclosed are populations of semiconductor nanocrystals, compositions and devices including a semiconductor nanocrystal capable of emitting light with an improved photoluminescence quantum efficiency. In one embodiment, a semiconductor nanocrystal includes a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light upon excitation with a photoluminescence quantum efficiency greater than about 65%.Type: ApplicationFiled: May 21, 2009Publication date: February 25, 2010Inventors: Dorai Ramprasad, Craig Breen, Jonathan S. Steckel
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Publication number: 20100044635Abstract: A semiconductor nanocrystal capable of emitting blue light upon excitation. Also disclosed are devices, populations of semiconductor nanocrystals, and compositions including a semiconductor nanocrystal capable of emitting blue light upon excitation. In one embodiment, a semiconductor nanocrystal capable of emitting blue light including a maximum peak emission at a wavelength not greater than about 470 nm with a photoluminescence quantum efficiency greater than about 65% upon excitation. In another embodiment, a semiconductor nanocrystal includes a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting blue light with a photoluminescence quantum efficiency greater than about 65% upon excitation.Type: ApplicationFiled: May 21, 2009Publication date: February 25, 2010Inventors: Craig Breen, Jonathan S. Steckel, Dorai Ramprasad
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Publication number: 20090230357Abstract: An electroluminescent phosphor comprising ZnS:Mn is disclosed. Also disclosed are ZnS:Mn electroluminescent phosphors that are free of or substantially free of copper, and/or wherein the phosphor has a D50 size of less than about 5 ?m. In addition, a method for preparing a ZnS:Mn phosphor is disclosed, comprising the steps of contacting at least a portion of each of a first solution comprising a Zn2+ compound, a manganese source, and a second solution comprising a S2? source agent; and then heating the mixture at a temperature and for a time sufficient to form a phosphor.Type: ApplicationFiled: March 11, 2009Publication date: September 17, 2009Inventors: Xianzhong Chen, Shellie Kaye Northrop, Chen-Wen Fan
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Publication number: 20090212256Abstract: A copper activated zinc sulfide electroluminescent phosphor is disclosed, wherein the phosphor comprises greater than about 1,000 ppm copper. Also disclosed is a copper activated zinc sulfide electroluminescent phosphor having a y color coordinate of at least about 0.480. A method for preparing the copper activated zinc sulfide electroluminescent phosphor is disclosed, comprising contacting a zinc sulfide, a first copper source, a magnesium source, and a lithium halide to form a first mixture; heating the mixture at a temperature and for a time sufficient to form a fired mixture; subjecting the fired mixture to a shear force capable of inducing a plurality of defects in the zinc sulfide lattice structure; and then contacting the fired mixture with a second copper source and a zinc oxide to form a second mixture; heating the second mixture at a temperature and for a time sufficient to form a second-fired material.Type: ApplicationFiled: February 26, 2009Publication date: August 27, 2009Inventors: Gregory Allan Marking, Xianzhong Chen, Shellie Kaye Northrop
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Publication number: 20090166587Abstract: To produce fluorescent bodies providing high brightness and high energy efficiency, a method of preparing a fluorescent body precursor is provided to enable an activator having a large ionic radius to be doped arbitrarily. The problems described above are solved by a method of preparing a fluorescent body precursor, which method is characterized by comprising applying a shock pressure of 0.1 GPa or higher to a mixture consisting essentially of a fluorescent body base, an activator, and a co-activating particle-growth promoter to dope the activator into the fluorescent body base in the presence of the co-activating particle-growth promoter.Type: ApplicationFiled: July 26, 2007Publication date: July 2, 2009Applicant: Kuraray Luminas Co., LtdInventors: Yoshihisa Tsuji, Hideharu Iwasaki
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Publication number: 20090159849Abstract: To provide a fluorescent having low toxicity and high quantum yield, and a method for producing the same. The fluorescent is a compound comprising each one of I, III and VI group elements having a chalcopyrite structure, has a particle diameter of 0.5 to 20.0 nm and a quantum yield of at least 3% but not more than 30% at room temperature. The fluorescent is produced by: mixing a first solution (solution A), which is prepared by dissolving and mixing copper (I) salt and indium (III) salt in a solution added with a complexing agent coordinating copper (I) and indium (III), with a second solution (solution C) in which a sulfur compound is dissolved; ripening the mixed solution for a predetermined amount of time as a pretreatment; heat-treating the ripened solution under predetermined heat conditions; mixing the ripened solution with the second solution (solution C); and heating thus obtained mixed solution under predetermined synthesis conditions.Type: ApplicationFiled: November 17, 2006Publication date: June 25, 2009Applicant: National Institute of Advanced Industrial Science and TechnologyInventors: Masato Uehara, Hiroyuki Nakamura, Hideaki Maeda, Masaya Miyazaki, Yoshiko Yamaguchi, Kenichi Yamashita
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Publication number: 20090121190Abstract: The present invention provides matrixes doped with semiconductor nanocrystals. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. The present invention also provides processes for producing matrixes comprising semiconductor nanocrystals.Type: ApplicationFiled: February 28, 2008Publication date: May 14, 2009Applicant: NANOSYS, INC.Inventors: J. Wallace Parce, Jian Chen, Robert S. Dubrow, William P. Freeman, Erik C. Scher, Jeffery A. Whiteford
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Publication number: 20090108235Abstract: The present invention provides semiconductor-nanoparticle-dispersed small silica glass particles that emit bright fluorescent light with high fluorescence quantum yield and high density, compared to the conventional semiconductor-nanoparticle-dispersed small glass particles, and that have excellent fluorescence intensity stability over time; and a process for preparing the same. The semiconductor-nanoparticle-dispersed silica glass particles have a mean particle size of not less than 10 nanometers and not more than 5 micrometers, and contain a hydrolyzed alkoxide and semiconductor nanoparticles at a concentration of not less than 2×10?5 mol/l and not more than 1×10?2 mol/l. The particles emit fluorescent light with a fluorescence quantum yield (quantum yield) of 25% or more (and 60% or more), when dispersed in a solution.Type: ApplicationFiled: September 21, 2006Publication date: April 30, 2009Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGYInventors: Masanori Ando, Norio Murase, Chunliang Li, Ping Yang
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Publication number: 20090039316Abstract: A doped-type metal sulfide phosphor nanoparticle, whose surface is modified with a surface modifier, the surface modifier being a compound of formula [I]: HS-L-W??Formula [I] wherein L is a divalent linking group; and W is COOM or NH2, in which M is a hydrogen atom, an alkali metal atom, or NX4, in which X is a hydrogen atom or an alkyl group; a dispersion containing the nanoparticle; and a method of producing the nanoparticle or the dispersion.Type: ApplicationFiled: October 3, 2008Publication date: February 12, 2009Applicant: FUJIFILM CORPORATIONInventors: Hiroyuki HIRAI, Keiko SUGIHARA, Junji NISHIGAKI
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Patent number: 7470379Abstract: The ionic conjugates include an inorganic particle electrostatically associated with a macromolecule which can interact specifically with predetermined chemical species or biological targets.Type: GrantFiled: March 16, 2005Date of Patent: December 30, 2008Assignees: Massachusetts Institute of Technology, The United States of America as represented by the Secretary of the NavyInventors: George P. Anderson, Hedi Mattoussi, J. Matthew Mauro, Moungi G. Bawendi, Vikram C. Sundar
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Patent number: 7462300Abstract: A doped-type metal sulfide phosphor nanoparticle, whose surface is modified with a surface modifier, the surface modifier being a compound of formula [I]: HS-L-W??Formula [I] wherein L is a divalent linking group; and W is COOM or NH2, in which M is a hydrogen atom, an alkali metal atom, or NX4, in which X is a hydrogen atom or an alkyl group; a dispersion containing the nanoparticle; and a method of producing the nanoparticle or the dispersion.Type: GrantFiled: November 8, 2004Date of Patent: December 9, 2008Assignee: FujiFilm CorporationInventors: Hiroyuki Hirai, Keiko Sugihara, Junji Nishigaki
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Publication number: 20080237540Abstract: The present invention provides methods for hermetically sealing luminescent nanocrystals, as well as compositions and containers comprising hermetically sealed luminescent nanocrystals. By hermetically sealing the luminescent nanocrystals, enhanced lifetime and luminescence can be achieved.Type: ApplicationFiled: March 19, 2008Publication date: October 2, 2008Applicant: NANOSYS, Inc.Inventor: Robert S. Dubrow
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Patent number: 7326366Abstract: A method of producing inorganic semiconductor- and phosphor-primary particles, which each comprises forming the particles by reacting at least one kind of precursor solution of the inorganic primary particle in a solvent, of which major component is water of a reacting vessel, under the conditions that the pressure is 0.2 to 20 MPa and the temperature is 120° C. to 370° C.; and inorganic semiconductor- and phosphor-primary particles produced by the method.Type: GrantFiled: October 20, 2004Date of Patent: February 5, 2008Assignee: Fujifilm CorporationInventors: Satoshi Aiba, Shigeharu Urabe
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Patent number: 7297295Abstract: A novel highly bright mechanoluminescence material free from decay of luminescence brightness even if repeated stress is applied, comprising a composite semiconductor crystal of the general formula xM1A1.(1-x)M2A2 (wherein each of M1 and M2 independently represents an atom selected from among Zn, Mn, Cd, Cu, Eu, Fe, Co, Ni, Mg and Ca, and each of A1 and A2 is an atom independently selected from among chalcogens, provided that M1A1 is different from M2A2; and x is a positive number less than 1); and a process for producing the same.Type: GrantFiled: July 11, 2003Date of Patent: November 20, 2007Assignees: Japan Science and Technology Agency, National Institute of Advanced Science and TechnologyInventors: Chao-Nan Xu, Morito Akiyama, Wensheng Shi
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Patent number: 7291291Abstract: There is presented an electroluminescent phosphor powder of copper-activated zinc sulfide particles that has a size distribution with a D50 value of less than 12 ?m, and more preferably less than 10 ?m. The powder is preferably made by a method that includes the steps of combining copper-doped zinc sulfide with sulfur, zinc oxide and a chloride-containing flux to form a first mixture; preliminarily firing the first mixture and milling the preliminarily fired first mixture to form a milled material having a D50 value of less than or equal to about 5 ?m; blending the milled material with sulfur, zinc oxide and a chloride-containing flux to form a second mixture; firing the mixture in a first firing step at a temperature in a range of about 1020° C. to about 1080° C. to form a hexagonal zinc sulfide material; inducing defects into the hexagonal zinc sulfide material; firing the hexagonal zinc sulfide material in a second firing step at a temperature in a range of about 650° C. to about 850° C.Type: GrantFiled: March 30, 2005Date of Patent: November 6, 2007Assignee: Osram Sylvania Inc.Inventors: Judy A. Belinski-Wolfe, Thomas A. Wolfe, Brian J. Payne
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Patent number: 7288216Abstract: An electroluminescent phosphor powder includes copper-activated zinc sulfide particles that have a size distribution with a D50 value of no more than 10 ?m, where no more than 25% of the particles have a size greater than about 15 ?m and/or a 24-hr brightness of at least 15 footlamberts. These particles are made by a method that includes first firing copper-doped zinc sulfide mixed with zinc oxide, sulfur and a chloride-containing flux, rapidly cooling the mixture to below 100° C., and then mulling and second firing the mixture to provide a powder. The powder can then be elutriated to provide the electroluminescent powder with a narrow particle size distribution (more than 90% between about 5 and 15 ?m). The elutriating step can be avoided (albeit with a slightly wider size distribution) by more tightly controlling the first firing temperature.Type: GrantFiled: March 30, 2005Date of Patent: October 30, 2007Assignee: Osram Sylvania Inc.Inventors: Xianzhong Chen, Shellie K. Northrop
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Patent number: 7264751Abstract: A yellow ZnS-based phosphor having improved color coordinates and luminance for use in intermediate- and low-voltage display devices using improved activators and coactivators has color coordinates (x, y) shifting to a yellow emission as the amount of an activator is increased. Therefore, the ZnS: (Au or Cu), In phosphor can be advantageously utilized for various display applications including vacuum fluorescent displays (VFDs) and field emission displays (FEDs).Type: GrantFiled: February 20, 2003Date of Patent: September 4, 2007Assignee: Samsung SDI Co., Ltd.Inventors: Sanghyuk Lee, Sanghoon Shin, Yongchan You, Joayoung Jeong
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Patent number: 7261838Abstract: The electroluminescent phosphor of this invention is comprised of zinc sulfide activated with copper and iodine and may produce an emission with an x color coordinate from 0.145 to 0.155 and a y color coordinate from 0.085 to 0.095. The phosphor preferably contains from about 0.08 to about 0.90 weight percent (wt. %) copper.Type: GrantFiled: December 28, 2004Date of Patent: August 28, 2007Assignee: Osram Sylvania Inc.Inventors: Judy A. Belinski-Wolfe, Brian J. Payne
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Patent number: 7252790Abstract: Zinc sulfide electroluminophores are prepared from solutions of zinc salts with hydrogen sulfide. The zinc sulfide compounds are mixed with activator and coactivator compounds to produce luminophores, and the mixtures are fired in the presence of fixing agents. These fired materials are then treated in an acid bath, washed, neutralized, and optionally filtered and dried.Type: GrantFiled: May 10, 2006Date of Patent: August 7, 2007Assignees: Leuchtstoffwerk Breitungen GmbH, Bundesdruckerei GmbHInventors: Frank Kappe, Benedikt Ahlers, Arnim Franz-Burgholz, Hans-Jurgen Limburg, Detlef Starick, Monika Voh
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Patent number: 7235190Abstract: A method for making a nanocrystal-based material capable of emitting light over a sufficiently broad spectral range to appear white. Surface-modifying ligands are used to shift and broaden the emission of semiconductor nanocrystals to produce nanoparticle-based materials that emit white light.Type: GrantFiled: September 2, 2004Date of Patent: June 26, 2007Assignee: Sandia CorporationInventors: Jess P. Wilcoxon, Billie L. Abrams, Steven G. Thoma
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Patent number: 7135130Abstract: The invention provides electroluminescent phosphor having superior luminance and a long life. The host material is ZnS.aAO, of which “A” is at least one element selected from among magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). “a” ranges from 0.001 to 0.01. Either one of or both copper (Cu) or manganese (Mn) is contained as an activator. At least one element selected from among chlorine (Cl), bromine (Br), iodine (I), and aluminum (Al) is contained as a co-activator. The luminance and life span of the electroluminescent phosphor can be increased by limiting “a”, which represents the proportion of alkaline earth metal oxide (AO) introduced into the zinc sulfide, within the range of 0.001 to 0.01.Type: GrantFiled: February 10, 2004Date of Patent: November 14, 2006Assignee: Nemoto & Co. Ltd.Inventors: Junya Watabe, Yoshiki Kanno, Shigenobu Matsumura
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Patent number: 7067072Abstract: The present invention relates in general to nanoparticles exhibiting luminescence such as photostimulated luminescence or photoluminescence and optical switching processes based upon such properties, in more particular, the use of such photostimulated luminescence exhibiting nanoparticles and switching nanoparticle for optical storage apparatuses and sensors as well as methods of making and using same.Type: GrantFiled: August 19, 2002Date of Patent: June 27, 2006Assignee: Nomadics, Inc.Inventor: Wei Chen
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Patent number: 7067073Abstract: A yellow ZnS-based phosphor which has improved color coordinates and luminance for use in intermediate- and low-voltage display devices using improved activators and coactivators is a (ZnS: Mn, Cu) phosphor which has color coordinates (x, y) shifting to a yellow emission as the amount copper added as an activator is increased. The phosphor has enhanced luminance by adding a trivalent metal as a coactivator. Therefore, the (ZnS: Mn, Cu) phosphor can be advantageously utilized for various display applications including vacuum fluorescent displays (VFDs) and field emission displays (FEDs).Type: GrantFiled: February 20, 2003Date of Patent: June 27, 2006Assignee: Samsung SDI Co., Ltd.Inventors: Sanghyuk Lee, Kyuchan Park, Sanghoon Shin, Yongchan You, Joayoung Jeong
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Patent number: 7067071Abstract: Zinc sulfide electroluminophores are prepared from solutions of zinc salts with hydrogen sulfide. The zinc sulfide compounds are mixed with activator and coactivator compounds to produce luminophores, and the mixtures are fired in the presence of fixing agents. These fired materials are then treated in an acid bath, washed, neutralized, and optionally filtered and dried.Type: GrantFiled: November 9, 2000Date of Patent: June 27, 2006Assignees: Bundesdruckeri GmbH, Leuchtstoffwerk Breitungen GmbHInventors: Frank Kappe, Benedikt Ahlers, Arnim Franz-Burgholz, Hans-Jürgen Limburg, Detlef Starick, Monika Voh
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Patent number: 7014793Abstract: A method of making zinc sulfide based electroluminescent phosphors is described wherein a first-fired zinc sulfide material having a hexagonal ?-ZnS crystal structure is at least partially converted to a distorted hexagonal ?-ZnS crystal structure by ultrasonic irradiation. The first-fired material is then fired at a lower temperature to form an electroluminescent phosphor.Type: GrantFiled: August 19, 2005Date of Patent: March 21, 2006Assignee: OSRAM SYLVANIA Inc.Inventors: Charles F. Chenot, Judy A. Belinski-Wolfe, Fuquiang Huang
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Patent number: 7008559Abstract: The present relates in general to upconversion luminescence (“UCL”) materials and methods of making and using same and more particularly, but not meant to be limiting, to Mn2+ doped semiconductor nanoparticles for use as UCL materials. The present invention also relates in general to upconversion luminescence including two-photon absorption upconversion, and potential applications using UCL materials, including light emitting diodes, upconversion lasers, infrared detectors, chemical sensors, temperature sensors and biological labels, all of which incorporate a UCL material.Type: GrantFiled: June 6, 2002Date of Patent: March 7, 2006Assignee: Nomadics, Inc.Inventor: Wei Chen
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Patent number: 7005086Abstract: A fluorescent substance is obtained by weighing and mixing CaS, Ga2S3, EuS and Ce2S3 in a mole ratio of (1-x):a:x:y (wherein 0.001?x?0.2, 0.0001?y?0.02 and 0.5?a?5) and by sintering the mixture. A light-emitting diode comprises an LED chip 2 and an LED chip sealing portion 5, made of silicone resin and including the fluorescent substance, for enclosing the LED chip 2. Hence, a fluorescent substance that is excited by light having a predetermined wavelength to emit light, a light-emitting diode having excellent luminous efficiency and luminous intensity, and a method for producing the fluorescent substance are attained by the present invention.Type: GrantFiled: November 6, 2003Date of Patent: February 28, 2006Assignee: Seiwa Electric Mfg. Co., Ltd.Inventor: Kenji Matsuno
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Patent number: 6921496Abstract: The ionic conjugates include an inorganic particle electrostatically associated with a macromolecule which can interact specifically with predetermined chemical species or biological targets.Type: GrantFiled: March 20, 2001Date of Patent: July 26, 2005Assignees: Massachusetts Institute of Technology, The United States of Americas as represented by the Secretary of the NavyInventors: George P. Anderson, Hedi Mattoussi, J. Matthew Mauro, Moungi G. Bawendi, Vikram C. Sundar
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Patent number: 6869545Abstract: The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.Type: GrantFiled: July 30, 2002Date of Patent: March 22, 2005Assignee: The Board of Trustees of the University of ArkansasInventors: Xiaogang Peng, Lianhua Qu
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Patent number: 6833086Abstract: A phosphor powder is composed of a host material made of an element coming under the group II of the periodic table and an element coming under the group VI of the periodic table, an activator and a co-activator, the amount ratio of the activator to the host material is 1×10−4 to 1×10−3 parts by weight when the amount ratio of the host material is 1 part by weight, and the co-activator has a molar concentration equal to a molar concentration of the activator.Type: GrantFiled: November 1, 2002Date of Patent: December 21, 2004Assignee: Sony CorporationInventor: Kazuo Kajiwara
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Patent number: 6787064Abstract: An improved method for the preparation of a dispersion of ZnS particles doped with copper is disclosed. The method comprises the step of performing a precipitation by mixing together a zinc salt, a sulfide, and a citrate or EDTA complex of copper ions, dissolved in several aqueous solutions. Enhanced luminescence is obtained.Type: GrantFiled: January 16, 2002Date of Patent: September 7, 2004Assignee: AGFA GevaertInventor: Hieronymus Andriessen
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Patent number: 6770221Abstract: A single-component white-emitting electroluminescent phosphor and its method of making are described. The single-component phosphor exhibits a white emission having an x color coordinate of 0.23 to 0.41 and a y color coordinate of 0.25 to 0.42. The phosphor is comprised of zinc sulfide activated with copper, manganese, chlorine, and, optionally, one or more metals selected from gold and antimony.Type: GrantFiled: February 14, 2003Date of Patent: August 3, 2004Assignee: Osram Sylvania Inc.Inventors: Xianzhong Chen, Robert L. Stevens
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Patent number: 6682664Abstract: An orange-yellow-emitting zinc sulfide-based electroluminescent phosphor is described wherein the phosphor has a brightness of greater than 10 foot-Lamberts. More particularly, the phosphor has a brightness of at least about 13 foot-Lamberts and an x color coordinate from about 0.51 to about 0.56 and a y color coordinate from about 0.42 to about 0.48. The zinc sulfide phosphor is activated with manganese, copper, chlorine, and a metal selected from gold and antimony.Type: GrantFiled: September 5, 2002Date of Patent: January 27, 2004Assignee: Osram Sylvania Inc.Inventors: Xianzhong Chen, Robert L. Stevens, Judy A. Belinski-Wolfe, Fuqiang Huang, Chen Wen Fan, Michael A. Maxwell
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Patent number: 6641756Abstract: A method for preparing a zinc sulfide phosphor having effective emission at low voltages. In the method for synthesizing a green-light emitting zinc sulfide based phosphor, ZnS:Cu, Al, which is applicable to a device operated with a low voltage, novel raw materials are employed. CuI is used as an activator, wherein monovalent copper (Cu1+) is complexed with ammonia and the ammonia complex is incorporated so as to uniformly distribute the activator in the mixture of raw materials. AlF3 is used as a co-activator, and, ZnI2 and NaI are added as iodide series fluxes. Thus, the color display characteristics are improved with a relatively high color purity and luminance.Type: GrantFiled: May 10, 2001Date of Patent: November 4, 2003Assignee: Samsung SDI Co., Ltd.Inventors: Soo-joung Lee, Jae-eun Jang
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Patent number: 6610217Abstract: A ZnS:Ag,Al phosphor and method of making are described wherein the ZnS:Ag,Al phosphor exhibits a substantially polyhedral morphology and low particle agglomeration. The method of making includes the use of a mixed sodium chloride and alkaline-earth metal chloride flux. The resulting ZnS:Ag,Al phosphors may be made into finished CRT phosphors having improved CRT screen making properties.Type: GrantFiled: July 23, 2001Date of Patent: August 26, 2003Assignee: Osram Sylvania Inc.Inventors: Gregory A. Marking, Courtney S. Warren, Brian J. Payne
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Patent number: 6444143Abstract: A water soluble semiconductor nanocrystal capable of light emission is provided, including a quantum dot having a selected band gap energy, a layer overcoating the quantum dot, the overcoating layer comprised of a material having a band gap energy greater than that of the quantum dot, and an organic outer layer, the organic layer comprising a compound having a least one linking group for attachment of the compound to the overcoating layer and at least one hydrophilic group space apart from the linking group by a hydrophobic region sufficient to prevent electron charge transfer across the hydrophobic region. The particle size of the nanocrystal core is in the range of about 12Å to about 150Å, with a deviation of less than 10% in the core. The coated nanocrystal exhibits photoluminescende having quantum yield of greater than 10% in water.Type: GrantFiled: May 29, 2001Date of Patent: September 3, 2002Assignee: Massachusetts Institute of TechnologyInventors: Moungi G. Bawendi, Frederick V. Mikulec, Jin-Kyu Lee
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Patent number: 6395196Abstract: An electroluminescent phosphor with an extended half-life is created by means of the present invention by taking an amount of a phosphor and treating it with antimony comprising the steps of placing an amount of antimony in an inert reaction vessel, placing a vapor permeable filter on top of the antimony, placing a phosphor with a given half-life on top of the vapor permeable filter, evacuating the reaction vessel below one atmosphere and heating it for a period of time to allow the antimony to react with the phosphor to produce a new phosphor with an extended half-life.Type: GrantFiled: July 3, 2000Date of Patent: May 28, 2002Assignee: Osram Sylvania Inc.Inventors: Richard G. W. Gingerich, Clarence D. Vanderpool
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Patent number: 6248261Abstract: An electroluminescent phosphor comprises zinc sulfide as a phosphor base material, at least one kind selected from copper and manganese as an activator, and at least one kind selected from chlorine, bromine, iodine, and aluminum as a coactivator. The content of alkaline earth metal elements in the electroluminescent phosphor is 0.05% by weight or less. In addition, the electroluminescent phosphor includes cesium in the range of 0.0001% by weight or more and 0.01% by weight or less. Such an electroluminescent phosphor has excellent brightness and life. An electroluminescent element comprises a phosphor layer in which an electroluminescent phosphor is dispersed in a dielectric. The electroluminescent phosphor includes reduced amount of alkaline earth metal elements and a slight amount of cesium.Type: GrantFiled: August 23, 1999Date of Patent: June 19, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Hirofumi Takemura, Yohe Shimizu, Takeshi Takahara, Mitsuhiro Oikawa
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Patent number: 6214257Abstract: A method of increasing the brightness of an electroluminescent phosphor comprises the steps of forming the phosphor as a base phosphor to have a given brightness; and annealing the base phosphor at a temperature and for a time sufficient to increase the given brightness of the base phosphor and form an annealed phosphor. Brightness can be increased from 8% to about 33% when measure against a control made by the same process but not annealed.Type: GrantFiled: June 7, 1999Date of Patent: April 10, 2001Assignee: Osram Sylvania Inc.Inventor: Butchi Reddy Vaddi
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Patent number: 6200496Abstract: A low-voltage excited white phosphor is provided. The white phosphor includes a ZnS:Zn phosphor and a (ZnnCd1−n)S:Ag,Cl phosphor (n=0.5 to 0.7), and has good color purity, high brightness and excellent color maintenance.Type: GrantFiled: October 7, 1999Date of Patent: March 13, 2001Assignee: Samsung Display Devices Co., Ltd.Inventors: Hyung-Keun Park, Sung-Kyoo Park