Sri International

Savin Corporation

Coloray Display Corporation

John B Mooney

Arden Sher

Ivor Brodie

A process is disclosed for forming shaped superconductors of the metal oxide type by electrophoretic deposition of superconducting particles which comprises providing particulate superconducting material of the metal oxide type coated with a fusible binder, electrophoretically depositing such coated superconducting particles on a substrate, heating the coated substrate sufficiently to fuse the binder to the substrate, fabricating the coated substrate into a desired shape, removing the binder, and then sintering the coated substrate to sinter the superconducting particles together. In a preferred embodiment the process further comprises immersing the coated substrate in an electrostatic field during the fusion step to both orient and maintain the superconducting particles in a desired direction.

Method of forming shaped superconductor materials by electrophoretic

A low dislocation density semiconductor device includes a first semiconductor layer of a III-V or II-VI semiconductor compound and alloying atoms on a non-metal substrate. The semiconductor compound usually has a large dislocation density. A predetermined position of the alloying atoms in the compound lattice structure can substantially reduce the compound dislocation density. Energy is applied to the alloying atoms so they are at the predetermined positions. The number of alloying atoms causes the semiconductor compound solubility limit to be exceeded. The layer is formed on a substrate of the III-V or II-VI semiconductor, such as gallium arsenide or another semiconductor, such as silicon or on an insulator such as sapphire. In the latter cases, the layer is formed on an intermediate layer having a lattice constant between that of the substrate and semiconductor compound. A second layer is epitaxially deposited on the first layer so both layers have virtually the same lattice constant and dislocation density. The alloying atoms are deposited by different energy assist methods, e.g. by an ion beam that irradiates the substrate, or by an energy assisted organometallic chemical vapor deposition process. The energy assist can be by ionization or optical irradiation causing topical heating of surface atoms deposited by the OMCVD process, without heating of the substrate or the underlying atoms. If the ion beam process is employed, the substrate is annealed such that the alloying atoms move from initial random locations thereof in the compound lattice to the predetermined locations.

Low dislocation density semiconductor device

Method of forming a low dislocation density semiconductor device

A method for the deposition of phosphor containing materials to CRT or VFD faceplates using reversal toning is dislosed. The method incudes the steps of charging the phosphor containing particles and the surface of a patterned photoresist with a charge of the same sign so that the particles are accurately deposited directly to an uncharged transparent surface electrode on the substrate. In a preferred embodiment, glass and/or polymeric binders may be included with the phosphor containing materials to enhance adherence to the substrate.

Deposition of cathodoluminescent materials by reversal toning

Method of making a low dislocation density semiconductor device

A photocapacitive image detector array comprises a matrix of M.times.N spaced columns of relatively high carrier concentration extending between first and second opposite faces of a semiconductor substrate having a relatively low carrier concentration. N parallel spaced electrode stripes extend in the X direction on the first face and M parallel spaced semiconductor stripes of intermediate carrier concentration extend in the Y direction on the second face. Stripe k of the N stripes makes ohmic contacts with each of the M columns, where k=1,2, . . . N. Stripe p of the M semiconductor stripes makes contact with each of the N columns, where p=1, 2, . . . M. Each of the M regions has a depletion layer having a thickness adapted to be modulated by radiation from an image to be detected. M parallel spaced electrode stripes extend in the Y direction so that stripe q of electrode stripes M is in registration with semiconductor stripe q, where q=1, 2, . . . M. A composite insulating layer, including two insulating thin films, is sandwiched between the M electrode stripes and M semiconductor stripes. Thereby M.times.N pixels are formed, with each pixel being associated with a different one of the columns. The composite insulating layer and M electrodes are transparent to radiation from the image so that the image incident on the semiconductor stripes modulates the thickness of the depletion layers of the semiconductor stripes to vary the capacitance at each pixel as a function of the radiation intensity incident thereon.

Photocapacitive detector array

A photovoltaic cell includes doped cadmium telluride formed of tetrahedral crystalline host semiconductor material including cadmium and telluride atoms bonded by ionic, covalent, and metallic forces. The host material is alloyed with Group II or VI atoms that replace either some of the host material cadmium or telluride atoms so that the alloyed and host atoms are bonded by at least covalent and metallic forces. The alloyed atoms have bond lengths with the nearest neighboring host atoms that are less than the host bond lengths. The number of bonded alloyed atoms is such that they do not substantially affect electronic conduction properties of the host material and result in a semiconductor region having no more than a few dislocations. A semiconductor of opposite conductivity to the conductivity type of the semiconductor region forms a junction with the region. At least one metal electrode makes ohmic contact with the first region. If the cadmium telluride is p type, the alloyed atoms are selected from the group consisting essentially of zinc, sulphur, and selenum, in which case the n type semiconductor can be cadmium sulphide. The n and p type semiconductors can be of the same compound to form a homojunction.

Photovoltaic cell including doped cadmium telluride, a dislocation

A solar cell in which the essential feature is a thin film of lead-cadmium-sulphide alloy. This alloy is preferably formed by spray pyrolysis from a solution containing the necessary ingredients. The solar cell advantageously takes the form of a homojunction constructed of two layers of lead-cadmium-sulphide alloy, with one of the layers being p-doped and the other of the layers being n-doped. The solar cell may be produced with an intrinsic layer interposed between the p-type layer and the n-type layer. The solar cell may also be made with a semiconductive layer of lead-cadmium-sulphide in contact with a metallic substrate.

Lead-cadmium-sulphide solar cell

A multilayer photoconductive assembly with an intermediate heterojunction. The assembly comprises a conductive substrate, a thin semiconductive layer formed of a material of one carrier polarity, which material has a narrow band gap. This layer is in substantially ohmic (low-resistive) contact with the conductive substrate. A light-absorbing layer is formed of a semiconductor which is thicker than the first layer and is of a carrier polarity opposite to the polarity of the first layer. The material has a band gap wider than the band gap of the first layer. The first and second semiconductive layers form a rectifying heterojunction therebetween. This enables the assembly to have a tremendously increased dark resistance and produces an assembly enabling high-speed electrophotography.

Multilayer photoconductive assembly with intermediate heterojunction

An electrophotographic photoconductor, formed on a conductive substrate by spray pyrolysis, comprising essentially a major amount of cadmium sulphide and a minor amount of zinc sulphide. The cadmium layer is at least three microns in thickness and is formed in three zones. The zone adjacent the metal substrate, adapted to form a contact layer, bears an amount of lead sulphide; the outermost zone, adapted to absorb light, is doped with a minor amount of copper to eliminate fatigue; and the intermediate zone, which is necessary to increase the surface potential, is adapted to transport light-generated charge and is doped with a minor amount of chlorine. The process is carried on in the atmosphere with three different aqueous solutions of reagents to form the three different zones. The photoconductive layer is microcrystalline in structure and bears adsorbed oxygen.

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San Jose, CA, United States of America

John B Mooney