Photoelectrochemical Characterization of Chemically Deposited Nanocrystalline Pb_0.2Hg_0.8S Thin Films

A room temperature chemical bath deposition method has been developed to grow nanocrystalline Pb_0.2Hg_0.8S thin films on to glass and fluorine doped tin oxide (FTO) coated glass substrate. The deposition bath consists of alkaline lead acetate, mercury acetate thiourea and ammonia. The preparative parameters such as ion concentration, deposition time, pH of the solution, deposition temperature were optimized to grow nanocrystalline Pb_0.2Hg_0.8S thin films. The as deposited films were studied for their structural, surface morphological, optical and electrical properties using sophisticated techniques such as X-ray diffraction (XRD), Optical absorption and dc-two probe method. The photo electrochemical (PEC) studies of Pb_0.2Hg_0.8S films were carried out, and the nanocrystalline films were found to be photoactive in polyiodide solution. From the current-voltage (I-V) characteristics, it is concluded that the Pb_0.2Hg_0.8S films are of p-type electrical conductivity. The photovoltaic output characteristics were used to calculate the fill factor (ff) and solar conversion efficiency (η).