Chemical Bath Deposition of Cd1−xZnxS as Buffer Layer in CIGS Solar Cell

Abstract

Cd1-xZnxS thin films were deposited on glass substrates by chemical bath deposition (CBD). The effect of ZnSO4 solution concentration on the properties of the thin films was analyzed. The concentration of ZnSO4 solution affects the deposition rate of Cd1-xZnxS thin films. When the deposition rate is low, Cd1-xZnxS cubic crystal phase is formed. The surface morphology of hexagonal Cd1-xZnxS thin films is denser than that of cubic phase, the lattice mismatch rate of cubic phase Cd1-xZnxS thin films and CIGS is lower, only 0.56%, the interfacial state density is lower. SCAPS software was used to simulate the performance of the buffer layer, and the conversion efficiency of the cubic phase Cd1-xZnxS buffer layer in CIGS Solar Cell was up to 23.50%. Based on the EDS results, the function relationship between the contents of Zn2+ and Cd2+ in the films and the band gap content was deduced.