Influence of cadmium acetate salt concentration on the composition, structure and morphology of Cd$_x$Pb$_{1-x}$S solid soluton films

Films of supersaturated substitutional Cd$_x$Pb$_{1-x}$S ($0.03 \leqslant x \leqslant 0.22$) solutions with a $B1$-type structure based on lead sulfide cubic lattice were produced by chemical bath co-deposition of CdS and PbS with various concentrations of cadmium acetate in the ammonium citrate reaction mixtures. The results of X-ray measurements showed that with increasing cadmium acetate concentration the microstrains increase in the deposited layers and the crystallites have [200] preferred orientation and pronounced volume anisotropy. It is shown that the obtained films are nanostructured. Depending on the solid solution composition, the layers consist of crystallites with average sizes 200–1000 nm. These, in turn, are formed from initial nanoparticles with diameter 50–70 nm. The conductivity of the films decreases with increasing cadmium-sulfide content. The synthesized films are photosensitive without any special sensitization procedure in the visible and near-infrared spectral ranges. The maximum of spectral characteristic and the long-wave limit of the photo-response of Cd$_x$Pb$_{1-x}$S films move smoothly toward the short-wave spectral range from 3.1 to 1.6 $\mu$m and from 2.5 to 1.2 $\mu$m, respectively, with an increase in the substitution level of lead into cadmium in PbS lattice correspondently.