Surface morphology and optical studies of non-aqueous Bi2S3 thin films

Abstract

A high purity, amorphous Bi2S3 thin film composed of loosely packed nanometer-sized spherical grains has been successfully deposited onto ITO substrate at room temperature from non-aqueous bismuth nitrate and sodium thiosulphate solution using a simple, inexpensive, reproducible, and environmentally friendly chemical route method. Film was characterized for structural, surface morphological, optical properties by means of X-ray diffraction ( XRD), scanning electron microscopy ( SEM) and UV-vis spectrometer, respectively. In last section, Bi2S3 film on ITO substrate was utilized in photo-electrochemical ( PEC) solar cell as a working and platinum as a reference electrode in presence of 80 mW/ cm(2) light intensity in lithium iodide as an electrolyte. Film of non-aqueous Bi2S3 exhibits two separate direct band transitions. Existence of two separate direct transitions was firstly noted in Bi2S3 thin films and explained its possible causes. PEC analysis confirms n-type conductivity.