Accession Number : AD0611181

Title :   INVESTIGATION OF THE PHYSICAL NATURE OF PHOTOELECTRIC TRAPPING AND RECOMBINATION CENTERS IN SINGLE CRYSTAL MATERIALS.

Descriptive Note : Final rept. for 15 Jun 61-14 Jun 64,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE CRYSTAL PHYSICS LAB

Personal Author(s) : Smakula,Alexander

Report Date : 22 DEC 1964

Pagination or Media Count : 91

Abstract : In continuation of our study of trapped charge carrier centers in KCl, RbCl, KBr, RbBr and in their solid solutions, the systems RbCl-RbBr and KBr-RbBr were investigated. Crystals of various compositions were irradiated with electrons, 3 Mev, 10,000 to 1,000,000 rads at temperatures 20C, -80C and -190C. The influence of radiation dose, irradiation temperature and crystal composition on spectral position, half width and intensity of the electron and hole trapped centers were studied. A variety of bands (M, F, K, V sub K, V sub 1 and V sub 2 and some others) were observed. In no case is the Mollwo relation valid. In solid solutions the shift of most bands does not go linearly with the composition but deviates toward lower energy. The half width of bands in solid solutions is always greater than in pure components. The concentration of trapped centers increases with irradiation, but at a decreasing rate. Most of the observed bands have been correlated to already-known models, but the correlation of some new ones (L sub x, V sub x) is still uncertain. (Author)

Descriptors :   (*SINGLE CRYSTALS, COLOR CENTERS), (*COLOR CENTERS, SINGLE CRYSTALS), ELECTRONS, ABSORPTION SPECTRA, MIXTURES, RUBIDIUM COMPOUNDS, POTASSIUM COMPOUNDS, CHLORIDES, BROMIDES, SOLID SOLUTIONS, ELECTRON TRANSITIONS, ATOMIC ENERGY LEVELS, OPTICAL ANALYSIS, ALKALI METAL COMPOUNDS, HALIDES, PHOTOELECTRIC MATERIALS, ABSORPTION

Distribution Statement : APPROVED FOR PUBLIC RELEASE