US 3,945,935 AGranted

Semiconductive metal chalcogenides of the type Cu.sub.3 VS.sub.4 and methods for preparing them

AssigneeMinnesota Mining and Manufacturing Company

InventorsBruce A. Torp, Edward C. Shaffer

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Abstract

Novel semiconductive tertiary and higher order type copper-Group V transition metal chalcogenides having useful broad-band photoconductive properties are characterized by containing fewer than 100 ppm of impurities as determined by electron microprobe analysis, excluding doping agents which may be present. These materials are made e.g. by chemical vapor transport methods using the powdered chalcogenide or mixtures of stoichiometric amounts of the elements of which it is composed, with a small amount of halogen or hydrogen halide and heating the mixture in vacuum in a temperature gradient in which the highest temperature is below about 1200.degree. C. Photoconducting devices can be made e.g. by supplying electrodes to a thin film of the material upon a dielectric substrate.

Claims17

Dependent claims

An inorganic single-phase composition characterized by having the formula unit

Cu.sub.3 MX.sub.4
wherein M is one stoichiometric equivalent containing from 1 to 3 elements selected from the group consisting of vanadium, niobium and tantalum, and X.sub.4 is four stoichiometric equivalents and consists of one or more elements of the group consisting of oxygen, sulfur, tellurium and selenium;
said composition being further characterized by having cubic crystal structure as shown by X-ray crystallographs, by containing fewer than 100 parts per million of non-dopant impurities as determined by electron probe analysis and by containing as dopant halogen of the group consisting of chlorine, bromine and iodine in amount of 0 to 100 parts per million and metal of the group consisting of arsenic and antimony in amount of 0 to 300 parts per million, said dopant materials being incorporated into the crystal lattice;
said compounds having electrical resistivity in unilluminated condition of more than 10.sup.5 ohm-centimeters and having an illuminated:unilluminated conductivity ratio of not less than about 10:1 and having broad-band photoconductive properties.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 05/193,701Filed 29 Oct 1971 · continuation in part
Priority: 21 Feb 1968
Granted: 23 Mar 1976
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

C30B 25/00
Single-crystal growth by chemical reaction of reactive gases
C30B 29/46
Inorganic compounds or compositions: sulfur-, selenium- or tellurium-containing compounds
C30B 29/48
Sulfur-, selenium- or tellurium-containing compounds: aIIBVI compounds wherein A is Zn, Cd or Hg, and B is S, Se or Te
C30B
Single-crystal growth