Feasibility study of Pb(1-x)Sn(x)Te charge coupled devices for infrared imaging applications

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Authors
Doshier, Alan Jeffrey
Subjects
Charge couple devices
Narrow gap semiconductors
Infrared imaging
Metal-Insulator-Semiconductor
Advisors
Tao, T. F.
Date of Issue
1973-03
Date
March 1973
Publisher
Monterey, California: Naval Postgraduate School
Language
eng
Abstract
The purpose of this thesis is to examine the feasibility of narrow-gap semiconductor charged coupled devices for infrared imaging applications. The semiconductors considered are PbTe for a three to five micron imager and Pb(.76)Sn(.24)Te for an eight to 12 micron imager, both operated at a temperature of 85 degrees K. Theoretical calculation of signal current and storage time are made based on the metal-insulate-semiconductor theory developed for silicon M-I-S devices. For a 0.1 degrees K temperature resolution of a 300 degree scene, signal currents are 4.8X10(-6) A/cm(2) for PbTe and 3.2X10(-2) A/cm(2) for PB(.76)Sn(.24)Te at a clocking frequency of 1 MHz. Storage times of 5.7X10(-5) seconds for PbTe and 1.27X10(-6) seconds for Pb(.76)Sn(.24)Te are calculated using a minority lifetime of 10(-7) seconds. Therefore, clocking frequencies higher than 1 MHz are recommended. Experimental studies of Pb(1-x)Sn(x)Te M-I-S were made which demonstrated that accumulation, depletion, and inversion layers can be controlled by gate voltage, following the general behavior of silicon M-I-S devices. A PbTe CCD infrared imager seems feasible. Feasibility of Pb(.76)Sn(.24)Te CCDs will require significant improvements in material and fabrication technology to increase storage time and reduce dark content.
Type
Thesis
Description
Series/Report No
Department
Department of Electrical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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