Proposition of an Environment Friendly Triple Junction Solar Cell Based on Earth Abundant CBTSSe/CZTS/ACZTSe Materials

We propose a triple junction CBTSSe/CZTS/ACZTSe solar cell using earth abundant and non-toxic CBTSSe, CZTS, and ACZTSe as the primary absorbing layers for top, middle, and bottom cells, respectively. Using rigorous optoelectronic simulation, we analyze the performance of the proposed cell and vary absorber thicknesses in order to maximize its efficiency. The maximum obtainable efficiency is calculated to be 36.04% with 2.73V open circuit voltage, 17.88mAcm(-2) short circuit current density, and 73.7% fill factor including Shockley-Read-Hall, surface and radiative recombination mechanisms. The maximum achievable efficiency can be obtained from an optimized device structure with 250, 300, and 1000nm thicknesses of CBTSSe, CZTS, and ACZTSe, respectively. The design and analyses presented in this work would help in achieving highly efficient eco-friendly inorganic solar cells.