A Numerical Approach to Design and Optimization of Highly Efficient CuInS₂/CMTS Based Tandem Solar Cell for Sustainable Energy Solution

This research is primarily focused on addressing the increasing worldwide demands for energy while minimizing environmental impact by developing renewable and efficient energy alternatives. The objective of this research is to examine and enhance the progress of a tandem solar cell that possesses thermal stability, cost-effectiveness, and exceptional efficiency in power generation. Chalcogenide materials are highly regarded as promising choices for the sub cells in tandem configurations. Copper Indium Disulfide (CuInS 2) is regarded as the upper sub cell, whereas Copper Manganese Tin Sulfide (CMTS) is chosen as the lower sub cell, ensuring appropriate alignment of their bandgaps. The work utilizes comprehensive modelling and optimization approaches through SCAPS-1D software to identify a highly promising combination, namely CuInS $\mathbf{I N O}_{2}$ CMTS, which achieves remarkable power conversion efficiency of 38.03%, excellent thermal stability of $\mathbf{- 0. 0 6 7 \%} \%{ }^{\circ} \mathrm{C}$, a short circuit current of $20.94 \mathrm{~mA} / \mathrm{cm}^{2}$, an open circuit voltage of $\mathbf{2. 2 0 8} \mathrm{V}$, and a fill factor of $\mathbf{8 2. 2 3 \%}$. During single cell simulation, for top and bottom cell, PCE was 18.34% and $\mathbf{2 6. 2 \%}$ respectively. Short circuit current in top, bottom and tandem cells was $20.91 \mathrm{~mA} / \mathrm{cm}^{2}, 20.93 \mathrm{~mA} / \mathrm{cm}^{2}, 20.94 \mathrm{~mA} / \mathrm{cm}^{2}$ respectively, which ensures current matching of these cells. During the designing, working temperature was maintained at 300K. Tandem solar cells, which exceed single-junction performances in both stability and efficiency, are widely acknowledged to be essential in determining the development of solar energy in the future. This research significantly contributes to the current attempts to pioneer novel and economically feasible solar technology using a paradigmatic approach. It has enormous implications for global energy sustainability projects.