Accession Number : AD0679566

Title :   RESEARCH ON IMPROVED II-VI CRYSTALS.

Descriptive Note : Final technical rept. 8 Mar 65-7 May 68,

Corporate Author : CLEVITE CORP CLEVELAND OHIO ELECTRONIC RESEARCH DIV

Personal Author(s) : Shiozawa,L. R. ; Jost,J. M. ; Sullivan,G. A.

Report Date : AUG 1968

Pagination or Media Count : 191

Abstract : This research program has been directed toward improving the quality of vapor-grown CdS, CdSe, and ZnTe crystals from the standpoint of both foreign impurities and intrinsic structural defects. Measurable improvements in purity of the final crystals have been obtained by specific purification steps, consisting of a sintering procedure and one or more fractional vacuum sublimations, applied to available semiconductor-grade material. Crystal quality as related to intrinsic defects has been improved, both during crystal growth and treatment after growth, through a better understanding of phase equilibria and point-defect equilibria and their relationships. A computer program has been set up and specific calculations were made for ZnTe. Evidence from diffusion experiments and from the examination of the void-precipitation phenomenon in ZnTe has shown that Zn vacancies are the significant intrinsic point defects in this material. Evaluation of crystal quality has primarily been placed on microscopic observations and electrical measurements such as photoconductivity, thermally-stimulated currents, and current oscillations.

Descriptors :   (*CRYSTAL GROWTH, *CADMIUM COMPOUNDS), (*SEMICONDUCTORS, CRYSTAL GROWTH), CADMIUM SULFIDES, CADMIUM SELENIDES, ZINC COMPOUNDS, TELLURIDES, SUBLIMATION, PURIFICATION, SINTERING, CRYSTAL DEFECTS, MICROSCOPY, PHOTOCONDUCTIVITY, DIFFUSION, COMPUTER PROGRAMMING, PHASE DIAGRAMS

Subject Categories : Crystallography
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE