Advancements of highly efficient perovskite based tandem solar cells

The past decade has witnessed the rapid development of perovskite solar cells, with their power conversion efficiency increasing from an initial 3.8% to over 26%, approaching the Shockley-Queisser (S-Q) limit for single-junction solar cells. Multijunction solar cells have garnered significant attention due to their tremendous potential to surpass the S-Q limit by reducing thermalization losses and wide light harvesting. The wide bandgap tunability of metal halide perovskite materials makes them highly suitable for sub-cells in tandem solar cells (TSCs). Currently, LONGi Green Energy Technology Co., Ltd. in China has set a world record efficiency of 34.6% based on a dual-junction perovskitesilicon TSCs, far surpassing the single-junction efficiencies of each sub-cell. Consequently, perovskite based TSCs are widely regarded as the next-generation photovoltaic products in the solar industry. Despite the significant efficiency improvements, several challenges still impede the commercial application of perovskite based TSCs, such as the instability of perovskite materials and difficulties in achieving large-scale production. This review summarizes the progresses and optimization strategies of perovskite based TSCs. This review also identifies the critical issues hindering multijunction solar cells. Finally, the potential solutions to address these challenges are proposed to advance the development of perovskite based TSCs.