Numerical Simulation of CGS/CIGS Single and Tandem Thin-film Solar Cells using the Silvaco-Atlas Software

Abstract

In this work, numerical simulations of single and double junction solar cells based copper gallium diselenide (CGS) and copper indium gallium diselenide (CIGS) electrical characteristics are performed using a physically based two-dimensional device simulator Silvaco-Atlas. The J-V characteristics and the external quantum efficiency EQE are simulated under AM1.5 illumination. In this study, where the single CGS solar cell used as the top cell and the single CIGS solar cell used as the bottom cell in the tandem configuration show conversion efficiencies of 18.92% and 20.32%, respectively. Our simulation results of the CIGS solar cell are in good agreement with the experimental high record efficiency. The simulated photovoltaic parameters of the CGS/CIGS tandem cell are: the short-circuit current density Jsc of 16.35 mA/cm2, the open circuit voltage Voc of 1.8 V and the fill factor FF of 85.09% and the conversion efficiency η of 25.11%. In the CGS/CIGS tandem solar cell, an improvement in the conversion efficiency to 25.11% was found. The overall investigation on copper indium gallium diselenide solar cells gives potential suggestions that may lead to the fabrication of the high efficiency CGS/CIGS single and tandem solar cells.