Optical Properties of a Thin Layer of Antimony Selenide Using Chemical Bath Deposition Method

Abstract

Optical properties of antimony selenide thin film synthesized for solar cell application via chemical bath deposition method (CBD) is presented in this research. Antimony trichloride and hydrogen selenide are the starting materials. The influence of varying concentration of Ethylenediaminetetra-acetic acid (EDTA), and Ammonia (NH3) at constant time in the deposition process remains the major landmark of this research. The optical properties of the resulting thin film was investigated. The thin films were characterized using M501single beam scanning UV-Vis spectrophotometer to analyze their optical absorption properties. It was seen that, transmittance appears to be higher at a lower concentration of EDTA and NH3. Transmittance attained a maximum value of 94% and 91% for variation of EDTA and NH3 respectively. Optical absorbance of Sb2Se3 thin film was found to be generally low even as concentration of EDTA and NH3 increased. The highest value of absorbance was found to be 17.5% which is low. Concerning optical reflectance, increase in the concentration of EDTA and NH3 did not produce increase in reflectance. The optical band gap of the thin film was determined using Taucs plot. The optical band gap for the variation of EDTA and NH3 was in the range of 3.5eV to 3.8eV and 3.7eV to 4.0eV respectively. These findings contribute to the understanding of the optical characteristics of Sb2Se3 thin film and proffers insight for optimizing their performance in photovoltaics. Characterization should be extended in the medium and far infra-red region so as to know the behavior of antimony selenide thin film in that region.