Studies on thin films of lead chalcogenides

A good deal of information regarding the synthesis and opto–electro-structural properties of thin films of lead chalcogenides have been revealed. The development of laser technology had opened up new application for narrow gap lead salts and their alloys. The polycrystalline thin films were deposited onto optically plane and chemically clean glass substrates by vacuum evaporation technique. The films were thin, uniform, smooth and tightly adherent to the substrates.Optical absorption spectroscopy, X-ray diffraction technique and current–voltage characteristics method were used to characterize the films. The absorption coefficients and optical band gaps of films were determined by using FTIR spectrophotometer. The nature of sample, crystal structure and lattice parameters of films were found from X-ray diffractograms. The dc conductivities and activation energies of films were measured in temperature range 300–380 K. Schottky junctions of PbS, PbSe and PbTe with indium metal were made. The barrier heights and ideality factors of these metal–semiconductor junctions were determined by using I–V characteristics.