Accession Number : ADA326653

Title :   Development of Infrared Photodetectors Based on InTISb Alloys (AASERT).

Descriptive Note : Final rept.,

Corporate Author : NORTHWESTERN UNIV EVANSTON IL CENTER FOR QUANTUM DEVICES

Personal Author(s) : Razeghi, Manijeh

PDF Url : ADA326653

Report Date : JUN 1997

Pagination or Media Count : 21

Abstract : The objective of this research program is to grow InTlSb alloys for long-wavelength infrared detector applications by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) and to investigate their physical properties. As a first step towards this goal, optimum growth conditions for high quality InSb epitaxial films on InSb, GaAs, and Si substrates have been determined. InSb films grown under these conditions exhibited one of the best structural and electrical properties reported so far. For the long-wavelength applications, growth of InAsSb and InTlSb was then carried out using arsine and cyclopentadienylthallium as the source for arsenic and thallium respectively. Growth of InAsSb with appropriate doping resulted in the room temperature operation of InAsSb photodetectors with extended cut-off wavelength. Incorporation of thallium into InSb has led to the first successful growth of InTlSb having an extended infrared response. By changing the thallium flow, thallium content was varied and the resulting absorption edge varied from 5.5 micrometers to 9.0 micrometers. The photoconductive detectors have been fabricated and measured using Fourier transform infrared (FTIR) spectrometer and blackbody test setup. Using the Hall data, the effective carrier lifetime and detectivity have been calculated for the InTlSb layers. The lifetime value ranged from 10 to 50 ns and detectivity was varied from 2 to 9 x 10(exp 8)cm-Hz(1/2)/W. at 77 K. These results demonstrate InTlSb as feasible material system for long wavelength infrared detection.

Descriptors :   *INDIUM ALLOYS, *ALLOYS, *INFRARED DETECTORS, *PHOTODETECTORS, *ANTIMONIDES, TEST AND EVALUATION, INFRARED DETECTION, FOURIER TRANSFORMATION, OPTIMIZATION, ENVIRONMENTS, PHYSICAL PROPERTIES, STRUCTURAL PROPERTIES, GROWTH(GENERAL), HALL EFFECT, GALLIUM ARSENIDES, FILMS, LOW PRESSURE, ORGANOMETALLIC COMPOUNDS, CHEMICAL VAPOR DEPOSITION, EPITAXIAL GROWTH, SUBSTRATES, ELECTRICAL PROPERTIES, ROOM TEMPERATURE, FAR INFRARED RADIATION, SILICON, OPERATION, DOPING, FLOW, ABSORPTION, ARSINES, INFRARED RADIATION, LONG WAVELENGTHS, BLACKBODY RADIATION, ARSENIC, THALLIUM ALLOYS.

Subject Categories : Properties of Metals and Alloys
      Infrared Detection and Detectors
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE