Influence of pH value on structure and optical properties of electrodeposited PbS thin films

摘要

PbS thin films were prepared on transparent conductive indium tin oxide glass substrates using a constant voltage cathodic electrodeposition method. The influence of solution pH on the phase compositions, surface morphologies and optical properties of the as deposited films was investigated. Results show that cubic PbS thin films with oriented growth along (111) and (200) direction can be obtained at pH=2.4, deposition voltage of 3 V, following deposition for 20 min with EDTA added as a complexing agent. The as deposited thin films exhibit a dense surface morphology. The compressive stress and optical bandgap of the PbS thin films first decrease and then increase with increasing pH value, and the bandgap of the thin films is calculated to be 0.38-0.39 eV.