Tuning the bandgap of Cd1-xZnxS (x = 0–1) buffer layer and CIGS absorber layer for obtaining high efficiency

Abstract This numerical study deals with the CIGS solar cell considering Cd1-xZnxS buffer layer. The composition ‘x’ of the buffer layer is determined and its impact on the solar cell performance parameters is studied. The influence of the buffer layer thickness on quantum efficiency is also discussed. The tuned bandgap and optimized thickness of the Cd1-xZnxS buffer layer are then utilized to obtain the suitable bandgap of the CIGS absorber layer. The maximum power conversion zone is revealed in terms of the CIGS bandgap and the impact of this bandgap on spectral response as well as performance parameters are discussed. The Cd0.6Zn0.4S/CIGS interface is studied by varying the defect density from 1010 cm−3 to 1016 cm−3. The cell performances are also analyzed for the temperature ranging from 260 K to 350 K.