The study of lead sulphide films. VI. Influence of oxidants on the chemically deposited PbS thin films

By treating the PbS films in H2O2 solution an increase of electrical resistance and photosensitivity (the last being about ten-fold greater) was observed. In the case of K2S2O8, a similar phenomenon was ascertained, but with a very high electrical resistance and a lower photosensitivity. The presence of PbSO4 in thin films was proved by IR spectroscopy. The SO42− content varies within the range 15–26 wt.%. The PbS films obtained in the presence of oxidants are characterized by electrical resistances which increase with the quantity of oxidant added. The photosensitivity has a maximum of 0.035 mol l−1 H2O2. The IR spectrum shows the appearance of lead cyanamide PbCN2 (13.1 wt.% in the sample with highest photosensitivity). The oxidation products and other detected impurities substantially influence the electrical and photoelectrical properties of PbS layers.