Electrochemical deposition of Cr3+ doped CuInSe2 thin films for electrocatalytic activity and photovoltaic performance

Abstract

Pure CuInSe2 and CuInSe2 thin films doped with different mole percentage concentrations (1 to 5 mol%) Cr3+were deposited through a one-step electrochemical deposition technique on an ITO glass substrate. The XRD pattern displayed the structural information of the pure CuInSe2 and Cr3+incorporated CuInSe2 thin films, where all elaborated films show tetragonal structure along with (200) plane orientation. The microstructural features of CuInSe2 thin films and Cr3+doped CuInSe2 have been examined with the help of an atomic force microscope, and the surface roughness was estimated. The AFM result shows the pure and Cr3+doped CuInSe2 thin films were homogeneous, nanocrystalline particles agglomerated, void-free, compact, and well-adhesive which reveals the films having a good morphology with a hillock structure. The EIS outcomes indicate that the CuInSe2 thin film obtained from 3 mol percent Cr3+ions doped CuInSe2 thin film shows very low charge transfer resistance, so it has high conductivity. Photoelectrochemical activity confirmed that 3 mol percent Cr3+ion doped CuInSe2 had superior photocurrent responsibility among them. It was observed from CV analysis that the optimized 3 mol percent of Cr3+ions doped CuInSe2 possessed greater electrocatalytic performance towards the reduction of I3-. The Raman spectrum of single crystallized CuInSe2 thin films shows that A1 dominates mode at174 cm-1. The Raman spectral studies confirmed that only the ternary phase of CuInSe2. Solar light irradiation with an intensity of 100 mW/cm2 on 3 mol% Cr3+ doped CuInSe2 thin film cell resulted in a power conversion efficiency of 8.23%.