Effect of Current Densities on Structural and Optical Properties of Brush Plated CuInSe2 (CIS)Thin films

CuInSe 2 (CIS)-based thin film compounds are considered one of the most efficient absorber materials for solar cell applications, now reaching conversion efficiencies as high as almost 20% for laboratory-sized devices. To make CIS-based thin films solar cells even more attractive and competitive, an alternative low cost process has to be developed for the manufacture of the high quality CIS absorber layers. In this work, CIS films were deposited by the brush plating technique for the first time. AR grade Copper sulphate (0.03M), Indium sulphate (0.05 M) and 0.005 M Selenium oxide was rsed for the deposition of films. The deposition current density was varied in the range of 10 – 100 mA cm-2. XRD analysis of the as-deposited films verified the existence of the main Bragg peaks for CIS in a chalco-pyrite crystal structure. The chemical composition of the films identiûed using XPS found to be copper rich. Tauc’s plot indicated a direct band gap of 0.99 eV. Surface morphology of the films indicated an increase of grain size and RMS value of surface roughness from 0.32 to 1.3 nm with depositon current density. Raman spectra of the films exhibited an intense peak at around 175 cm 1. This peak can be assigned to the A 1 mode of CIS. Photoelectrochemical cell (PEC) studies indicated an open circuit voltage of 0.49V and short circuit current density of 13 mA cm-2 for the films deposited at 100 mA cm-2. The photo output increased with deposition current density.