Patents by Inventor Richard B. Schoolar
Richard B. Schoolar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 4482881Abstract: A semiconductor photoconductor having low impedance nonmetallic contacts is disclosed which has increased detectivity over prior art photoconductor structures. The improved photoconductor has metallic contacts that are separated by a contact length that is greater than the optical length of the detector. The contact regions of the semiconductor adjacent the detector region are thicker than the detector region. The process for fabricating the photoconductor includes thinning the detector region to an appropriate thickness while preserving the greater thickness of the contact regions.Type: GrantFiled: July 19, 1982Date of Patent: November 13, 1984Assignee: The Aerospace CorporationInventors: Richard B. Schoolar, Alfred A. Fote
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Patent number: 4371232Abstract: A variable temperature method for the preparation of single and multiple taxial layers of single-phase (e.g., face-centered cubic), ternary lead chalcogenide alloys (e.g., lead cadmium sulfide [Pb.sub.1-w Cd.sub.w ].sub.a [S].sub.1-a wherein w varies between zero and fifteen hundredths, inclusive, and a=0.500.+-.0.003), deposited upon substrates of barium fluoride, BaF.sub.2, maintained in near thermodynamic equilibrium with concurrently sublimated lead alloy and chalcogenide sources. During preparation, the temperature of the substrate is varied, thereby providing an epilayer with graded composition and predetermined electrical and optical properties along the direction of growth. This growth technique can be used to produce infrared lenses, narrowband detectors, and double heterojunction lasers.Type: GrantFiled: April 25, 1980Date of Patent: February 1, 1983Assignee: The United States of America as represented by the Secretary of the NavyInventors: James D. Jensen, Richard B. Schoolar
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Patent number: 4339764Abstract: A high temperature method for the preparation of single and multiple epitaxial layers of single-phase lead sulfide-selenide, [Pb].sub.a [S.sub.x Se.sub.1-x ].sub.1-a wherein x varies between one and zero, inclusive, and a=0.500.+-.0.003, deposited upon substrates of barium fluoride, BaF.sub.2, maintained in near thermodynamic equilibrium with concurrently sublimated lead alloy and chalcogenide sources. During preparation, the substrate is exposed to the vapor emanating from the single chimney of a two-zone, dual-chamber furnace, thereby providing an epilayer of uniform, and predetermined electrical and optical properties.Type: GrantFiled: March 26, 1979Date of Patent: July 13, 1982Assignee: The United States of America as represented by the Secretary of the NavyInventor: Richard B. Schoolar
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Patent number: 4312114Abstract: A thin-film single-crystal infrared detector exhibiting an increased frequency of response. A closed transverse junction, formed by diffusing a central electrode of an impurity rich metal into a lead-salt film epitaxially grown on an insulating substrate, provides an effective optical area in excess of the junction surface. An ohmic contact is spaced apart from the central electrode. Junction capacitance, a limitation upon the electrical response, is diminished by the detector geometry while detectivity is enhanced. In an alternative embodiment the detector may be segmented to provide directional detection.Type: GrantFiled: February 28, 1979Date of Patent: January 26, 1982Assignee: The United States of America as represented by the Secretary of the NavyInventor: Richard B. Schoolar
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Patent number: 4282045Abstract: A variable temperature method for the preparation of single and multiple epitaxial layers of single-phase (e.g., face-centered cubic), ternary lead chalcogenide alloys (e.g., lead cadmium sulfide, [Pb.sub.1-w Cd.sub.w ].sub.a [S].sub.1-a wherein w varies between zero and fifteen hundredths, inclusive, and a=0.500.+-.0.003), deposited upon substrates of barium fluoride, BaF.sub.2, maintained in near thermodynamic equilibrium with concurrently sublimated lead alloy and chalcogenide sources. During preparation, the temperature of the substrate is varied, thereby providing an epilayer with graded composition and predetermined electrical and optical properties along the direction of growth. This growth technique can be used to produce infrared lenses, narrowband detectors, and double heterojunction lasers.Type: GrantFiled: April 25, 1980Date of Patent: August 4, 1981Assignee: The United States of America as represented by the Secretary of the NavyInventors: James D. Jensen, Richard B. Schoolar
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Patent number: 4263604Abstract: A variable temperature method for the preparation of single and multiple taxial layers of single-phase (e.g., face-centered cubic), ternary lead chalcogenide alloys (e.g., lead cadmium sulfide, [Pb.sub.1-w Cd.sub.w ].sub.a [S].sub.1-a where w varies between zero and fifteen hundredths, inclusive, and a=0.500.+-.0.003), deposited upon substrates of barium fluoride, BaF.sub.2, maintained in near thermodynamic equilibrium with concurrently sublimated lead alloy and chalcogenide sources. During preparation, the temperature of the substrate is varied, thereby providing an epilayer with graded composition and predetermined electrical and optical properties along the direction of growth. This growth technique can be used to produce infrared lenses, narrowband detectors, and double heterojunction lasers.Type: GrantFiled: April 25, 1980Date of Patent: April 21, 1981Assignee: The United States of America as represented by the Secretary of the NavyInventors: James D. Jensen, Richard B. Schoolar
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Patent number: 4231053Abstract: A thin-film single-crystal infrared detector exhibiting an increased freqcy of response. A closed transverse junction, formed by diffusing a central electrode of an impurity rich metal into a lead-salt film epitaxially grown on an insulating substrate, provides an effective optical area in excess of the junction surface. An ohmic contact is spaced apart from the central electrode. Junction capacitance, a limitation upon the electrical response, is diminished by the detector geometry while detectivity is enhanced. In an alternative embodiment the detector may be segmented to provide directional detection.Type: GrantFiled: March 5, 1979Date of Patent: October 28, 1980Assignee: The United States of America as represented by the Secretary of the NavyInventor: Richard B. Schoolar
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Patent number: 4227948Abstract: A variable temperature method for the preparation of single and multiple taxial layers of single-phase (e.g., face-centered cubic), ternary lead chalcogenide alloys (e.g., lead cadmium sulfide, [Pb.sub.1-w Cd.sub.w ].sub.a [S].sub.1-a wherein w varies between zero and fifteen hundredths, inclusive, and a=0.500.+-.0.003), deposited upon substrates of barium fluoride, BaF.sub.2, maintained in near thermodynamic equilibrium with concurrently sublimated lead alloy and chalcogenide sources. During preparation, the temperature of the substrate is varied, thereby providing an epilayer with graded composition and predetermined electrical and optical properties along the direction of growth. This growth technique can be used to produce infrared lenses, narrowband detectors, and double heterojunction lasers.Type: GrantFiled: December 27, 1977Date of Patent: October 14, 1980Assignee: The United States of America as represented by the Secretary of the NavyInventors: James D. Jensen, Richard B. Schoolar
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Patent number: 4157926Abstract: A thin-film single-crystal infrared detector exhibiting an increased frequency of response. A closed transverse junction, formed by diffusing a central electrode of an impurity rich metal into a lead-salt film epitaxially grown on an insulating substrate, provides an effective optical area in excess of the junction surface. An ohmic contact is spaced apart from the central electrode. Junction capacitance, a limitation upon the electrical response, is diminished by the detector geometry while detectivity is enhanced. In an alternative embodiment the detector may be segmented to provide directional detection.Type: GrantFiled: June 22, 1978Date of Patent: June 12, 1979Assignee: The United States of America as represented by the Secretary of the NavyInventor: Richard B. Schoolar
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Patent number: 4154631Abstract: A high temperature method for the preparation of single and multiple epitaxial layers of single-phase lead sulfide-selenide, [Pb].sub.a [S.sub.x Se.sub.1-x ].sub.1-a wherein x varies between one and zero, inclusive, and a=0.500.+-.0.003, deposited upon substrates of barium fluoride, BaF.sub.2, maintained in near thermodynamic equilibrium with concurrently sublimated lead alloy and chalcogenide sources. During preparation, the substrate is exposed to the vapor emanating from the single chimney of a two-zone, dual-chamber furnace, thereby providing an epilayer of uniform, and predetermined electrical and optical properties.Type: GrantFiled: May 27, 1977Date of Patent: May 15, 1979Assignee: The United States of America as represented by the Secretary of the NavyInventor: Richard B. Schoolar
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Patent number: 4126732Abstract: The process of coating epitaxial films of lead chalcogenide materials with s.sub.2 S.sub.3 to insulate the films from the effects of oxygen upon exposure to air.Type: GrantFiled: August 16, 1977Date of Patent: November 21, 1978Assignee: The United States of America as represented by the Secretary of the NavyInventors: Richard B. Schoolar, James D. Jensen