The Energy Gap and Optical Constants of Thin PbS Films

Abstract

Polycrystalline PbS alloy was prepared successfully in evacuated quartz tube, from which thin PbS film was prepared by thermal evaporation technique. Specimen was deposited on quartz crystal and the thickness of the film was 800Å. From FTIR spectrophotometer, the optical properties of thin PbS film were determined in the range of (1-4.5)μm.The energy gap of PbS film was found to be direct gap of 0.34 eV. The optical constants were determined also.