GROWTH AND CHARACTERIZATION OF PBS DEPOSITED ON FERROELECTRIC CERAMICS

The growth and properties of PbS thin films, chemically deposited on b ull; lead titano-zirconate ceramics, are investigated. Scanning electr on microscopy photographs reveal that the medium size of crystallites is much larger for PbS films grown on poled ferroelectric substrates t han for the films grown onto glass or onto unpoled ferroelectric subst rates. In the first case the medium size of crystallites is about 1-1. 5 mu m while in the second case it is less than 0.3 mu m. Spectral dis tribution of photoconductivity and thermally stimulated currents (TSC) measurements were performed on all samples. Experimental results indi cate that the properties of the PbS films can vary, depending on the s ubstrate nature and in the case of poled ferroelectric substrates, on the polarity. The photoconductive signal is usually larger, the dark r esistivity is smaller, and the TSC current value is higher for PbS fil ms deposited on the positive face of the ferroelectric substrate than for those deposited on the negative face. (C) 1995 American Institute of Physics.