POLYCRYSTALLINE LEAD SELENIDE THIN-FILMS - GROWTH FROM SOLUTION AND PROPERTIES

The preparation of lead selenide thin films from an alkaline medium co nsisting of Pb2+ and Se2- ions is presented. The growth kinetics and r eaction mechanism are also discussed. The electrical conductivity is m easured in the 300-700 K temperature range and the activation energies of the electrical conduction, both in the extrinsic and intrinsic con duction regions, have been determined. The room temperature electrical conductivity is of the order of 10(-6) ohm(-1) cm(-1) and the electri cal conduction is of the p-type. The charge carrier concentration (n) and mobility (mu) are determined from the conductivity and thermo powe r measurement data and the order of the observed carrier concentration is 10(19) cm(-3). Both the carrier concentration and mobility have be en found to be increased with increasing temperature. The XRD studies for as-grown sample showed PbSe to be crystalline face centred cubic. The calculated lattice parameter, a, is 6.124 Angstrom. Annealing of t he sample showed increase in the peak intensities with some additional peaks introduced. The grain size is found to be improved from 509 Ang strom to 735 Angstrom after anneling.