Photoelectrochemical cell performances of Cu2ZnSnSe4 thin films deposited on various conductive substrates

This work studies the influence of various conductive substrates such as Al, Cu and Ag on the optical and photoconductive behavior of Cu2ZnSnSe4 (CZTSe) thin films prepared using thermal evaporation method. The XRD analysis indicates that the deposited CZTSe films are tetragonal structure for all substrates, however, the compound prepared using glass substrates shows some secondary phases. The SEM images show spherical particles for all the films. The films show dense and uniform surface and no voids are observed. EDX analysis witnesses for the deposition compound that exhibits near stoichiometric values. CZTSe thin films show the absorption coefficient about 104 cm−1 and the band-gap is found to be about 1.15 eV, 1.32 eV, 1.4 eV and 1.19 eV for CZTSe films deposited on glass, Al, Cu and Ag substrates respectively. From, the Mott-Schottky Plot, the CZTSe thin films confirms p-type conductivity and the J-V plot of CZTSe thin films shows the photoactivity. The CZTSe films deposited on Al substrates show higher PCE.