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:
Mar. 30, 1993
Filed:
Nov. 12, 1991
Chan-Shin Wu, Torrance, CA (US);
Cheng P Wen, Mission Viejo, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A multiple quantum well superlattice radiation detector is compositionally graded to establish an internal electric field within the superlattice that allows the device to operate with a reduced or zero externally applied bias voltage. The compositional grading can be implemented by grading the doping levels of successive quantum wells or the relative proportions of elements in successive barrier layers of the superlattice, or by a combination of the two. If a tunneling current blocking layer is employed, it can also be compositionally graded to inhibit a substantial increase in the blocking layer's barrier energy level near a charge carrier collector on the other side of the blocking layer from the superlattice. The charge carrier collector can itself be provided with a graded dopant concentration near the blocking layer to inhibit reverse bias voltage breakdown in the blocking layer.