Perovskite-Based Tandem Solar Cells: Get the Most Out of the Sun

Tandem solar cells (TSCs) comprising stacked narrow-bandgap and wide-bandgap subcells are regarded as the most promising approach to break the Shockley-Queisser limit of single-junction solar cells. As the game-changer in the photovoltaic community, organic-inorganic hybrid perovskites became the front-runner candidate for mating with other efficient photovoltaic technologies in the tandem configuration for higher power conversion efficiency, by virtue of their tunable and complementary bandgaps, excellent photoelectric properties, and solution processability. In this review, a perspective that critically dilates the progress of perovskite material selection and device design for perovskite-based TSCs, including perovskite/silicon, perovskite/copper indium gallium selenide, perovskite/perovskite, perovskite/CdTe, and perovskite/GaAs are presented. Besides, all-inorganic perovskite CsPbI(3)with high thermal stability is proposed as the top subcell in TSCs due to its suitable bandgap of approximate to 1.73 eV and rapidly increasing efficiency. To minimize the optical and electrical losses for high-efficiency TSCs, the optimization of transparent electrodes, recombination layers, and the current-matching principles are highlighted. Through big data analysis, wide-bandgap perovskite solar cells with high open-circuit voltage (V-oc) are in dire need in further study. In the end, opportunities and challenges to realize the commercialization of TSCs, including long-term stability, area upscaling, and mitigation of toxicity, are also envisioned.