Accession Number : ADA017524

Title :   Chemical Vapor Deposition of Chalcogenide Semiconductors.

Descriptive Note : Final technical rept. 1 Jul 73-31 Dec 74,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE CENTER FOR MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Bowen,H. Kent ; VanderSande,J.

Report Date : AUG 1975

Pagination or Media Count : 110

Abstract : Polycrystalline CdTe was prepared by vapor deposition. The elements were vaporized and carried to the reaction chamber using He + 8% H2 as the carrier gas (all at 1 atm total pressure). Deposition rates were 0.1-0.01 mm/hr at temperatures between 725-785C. Columnar grains and micron size pores were found in all samples. Electrical property measurements and x-ray texture studies were made. Transmission electron microscopy elucidated the nature of precitates and voids (50-100 A) in the as grown material and material from other sources. Scattering theory calculations indicate orders of magnitude agreement with the observed absorption coefficients at 10.6 micrometers. A new absorption measuring technique was developed capable of determining beta accurately on small samples. The thermal shift in the fundamental absorption edge due to infrared absorption (10.6 micrometers) was used. Both the theory and measurement system were defined.

Descriptors :   *Infrared windows, *Laser materials, *Crystal growth, *Cadmium tellurides, Vapor deposition, Infrared optical materials, Infrared lasers, Absorption(Physical), Optical properties, Electron microscopy, Crystal defects, Electrical properties, X ray diffraction

Subject Categories : Lasers and Masers
      Crystallography
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE