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:
Dec. 19, 1995
Filed:
Jun. 25, 1993
Kwong-Kit Choi, Tinton Falls, NJ (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A semiconductor infrared detector having a transistor structure with a superlattice base. The superlattice base is between a multiple quantum well (MQW) structure and an electron energy high pass filter. The superlattice base restricts electrons to minibands resulting in no overlap in energy between the energies of the photoelectrons and the dark electrons. As a result, more photoelectrons reach the collector, and the emitter to collector photocurrent transfer ratio is increased. The increased transfer ratio results in increased sensitivity of the detector. The superlattice base between the MQW structure and the electron energy high pass filter comprises multiple alternating wells and barriers. The wells are preferably made of GaAs and the barriers are preferably made of Al.sub.x Ga.sub.1-x As, where x is equal to 0.25. However, alternate embodiments may include all the combinations of the Al molar ratio x in the barriers in the light sensitive MQW region, the superlattice base, and the electron energy high pass filter. The minibands created in the superlattice base confines the photoelectrons into a miniband by reducing the phonon emission rate, and removing the available states between the minibands.