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

1996; Elsevier BV; Volume: 41; Issue: 2 Linguagem: Inglês

10.1016/s0921-5107(96)01611-x

1873-4944

Cristina Naşcu, Valentina Vomir, Ileana Pop, Violeta Ionescu, Rodica Grecu,

Advanced Thermoelectric Materials and Devices

Abstract By treating the PbS films in H 2 O 2 solution an increase of electrical resistance and photosensitivity (the last being about ten-fold greater) was observed. In the case of K 2 S 2 O 8 , a similar phenomenon was ascertained, but with a very high electrical resistance and a lower photosensitivity. The presence of PbSO 4 in thin films was proved by IR spectroscopy. The SO 4 2− 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 H 2 O 2 . The IR spectrum shows the appearance of lead cyanamide PbCN 2 (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.