The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 1978
Filed:
Feb. 09, 1976
Hiroshi Kimura, Los Angeles, CA (US);
Hughes Aircraft Company, Culver City, CA (US);
Abstract
Large bulk single crystals of lead tin telluride are synthesized by first mixing desired amounts of lead, tin and tellurium with, if desired, bismuth and reacting the mixture at 950.degree. C to form a source material. The source material is then converted into a single crystal by recrystallization and digestion in a uniform 850.degree. C to 860.degree. C temperature zone in order to prevent transport of material and, hence, variations in composition. Thereafter, these crystals, which are doped with bismuth, or crystals made by Bridgman or Czochralski growth, are cut into wafers and isothermally annealed at 600.degree. C to 650.degree. C under a metal-rich vapor pressure obtained from metal-rich lead tin telluride powder. Lowering of temperature to about 200.degree. C and further annealing is capable of converting p-type crystals to n-type crystals. The result of annealing, whether p-type, n-type, or intrinsic, is a low carrier concentration, high mobility crystal.