Investigation of Optical and Electrical Properties of Wide Band Gap Materials
Final rept. Jun 1972-Dec 1975
DAYTON UNIV OH DEPT OF PHYSICS
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This report concerns research on the optical and electrical properties of I-III-VI2 chalcopyrite compounds, HgS, ZnSe, and GaAs. Seventeen of the I-III-VI2 compounds were grown by melt-growth and vapor-phase method. HgS crystals were mainly grown by a modified iodine transport technique with small addition of NH4Cl. Anmalous temperature dependence of energy gaps in I- III-VI compounds having d-electron was determined for AgGaS2 and CuInSe2 from photoluminescence, absorption, and reflection and was explained by the temperature dependent p-d hybridization. Broad-band luminescence dominating in AgGaS2 and CuInSe2 was influenced by heat-treatment, which indicates that intrinsic defects are responsible for the band. The electrical transport measurements lead to an understanding of the role of intrinsic defects in conduction mechanisms in CuGaS2, AgGaS2, CuInSe2, and ZnSe. Homojunction diode in CuInSe2 was prepared by both diffusion and implantation techniques using Cd, Br, Zn and Cl. The p-n junction showed efficient electroluminescence as well as efficient photodetection characteristics. In GaAs, the oscillatory photoconductivity was observed.
- Solid State Physics