Optical absorbance enhancement by electrochemical surface roughening of CuInS₂ thin films

Abstract

This work presents a simple electrochemical etching method to increase the surface roughness of copper indium disulphide (CIS) thin films using low concentration of hydrochloric acid. Film morphologies were investigated using scanning electron microscopy and atomic force microscopy. The structure of films was investigated using x-ray diffraction. A comparative study of optical properties of as-deposited and roughened CIS thin films by transmittance and reflectance experiments show a strong enhancement of absorbance for wavelengths between 600 and 900 nm.