Perovskite/silicon tandem solar cells have reached certified efficiencies of 28% (on 1 cm² by Oxford PV) in just about 4 years, mostly driven by the optimized design in the perovskite top cell and crystalline silicon (c-Si) bottom cell. In this review, we focus on the structural adjustment of the bottom cell based on the structural evolution of monolithic perovskite/silicon tandem solar cells to improve their performance. To begin with, c-Si solar cells are classified into silicon homojunction and silicon heterojunction (SHJ) devices according to temperature tolerance, and the corresponding structural features are presented. Then, the evolution of monolithic perovskite/silicon tandem cells based on c-Si homojunction and heterojunction bottom devices is summarized. An appropriate candidate of the c-Si bottom cell for monolithic perovskite/silicon tandem cells is proposed, mainly including passivated emitter and rear cell devices, the tunnel oxide passivated contact cell, and SHJ devices. In brief, our review will emphasize the important role of the c-Si bottom cell with different passivation structures for perovskite/silicon tandem cells, which provides a guidance to enhance the performance of tandem cells.

Perovskite/silicon tandem solar cells (TSCs) have the potential to achieve power conversion efficiency exceeding 30%. To be compatible with high-efficiency solution-deposited perovskite top cell, a planar front surface for silicon bottom cell is generally required. However, flat front surfaces result in large light reflection losses and thus reduce the performance of tandem device. To boost light absorption, we design light management antireflective foils made from polydimethylsiloxane (PDMS) polymer carrying random-pyramidal textures with three different pyramid size ranges (1–3 µm, 3–8 µm, 8–15 µm). The optical properties, together with the reflection behavior applied to perovskite/silicon tandem solar cells have been systematically studied. One of the PDMS layer exhibited a relatively strong light-scattering property with a high average haze ratio originated from synergistic effect of the appropriate pyramid size and the uneven random pyramid distribution. Consequently, the short-circuit current density of the tandem device was improved by 1.72 mA/cm² and thus its efficiency increased from 19.38% to 21.93%, after laminating the PDMS-based antireflection coating (ARC) onto the front surface of tandem device. Furthermore, this work provides a facile and cost-effective way to introduce light-management foils and indicates a broad strategy to enhance the performance of solar cells with planar front surface.