Highly Efficient 3D–2D Perovskite Tandem Solar Cells: A Combined Ray Tracing and Transfer Matrix-Based Simulation Study

Perovskite solar cells have garnered considerable interest as a promising option for next-generation photovoltaics due to their low-cost fabrication, high efficiency, and bandgap tunability. However, the bottleneck for their practical feasibility is their low stability and toxicity. To tackle the stability concerns of 3D perovskites, 2D layer perovskites, namely Ruddlesden-Popper (RP) and Dion-Jacobson (DJ), have emerged as a potential alternative. This study employs a DJ perovskite layer due to its ability to address the inherent weak Van der Waals gaps between layers found in RP, leading to enhanced stability. Further, to obtain high efficiency by using the wide absorption spectrum, a CH 3 NH 3 PbI 3 (1.55 eV) perovskite is employed as a top cell in tandem with DJ (1.1 eV) as a bottom cell. To mitigate the hysteresis issues of the top MAPbI 3 layer, PCBM/CeO 2 is introduced as an electron transport layer (ETL). Furthermore, a 30-nm-thick carbon nanotube is employed to enhance the moisture stability of the top CH 3 NH 3 PbI 3 layer. To analyze the maximum conversion efficiency of the proposed CH 3 NH 3 PbI 3 -DJ perovskite tandem solar cell, the thickness of both perovskite layers is optimized. The tandem solar cell is evaluated using two computational approaches, the ray tracing method (RTM) and the transfer matrix method (TMM). This study provides an exhaustive comparison of these two methods in terms of their impact on PV performance, a comparison that has not been previously explored in the literature. The results show that the RTM/TMM yield optimized thickness of 150 nm/150 nm and 500 nm/400 nm for the top and bottom perovskite layers, respectively. The maximum efficiency achieved using the RTM and TMM is 27.03% and 23.49%, respectively.