Drivers of Efficiency Breakthroughs: Key Technological Advances in Monolithic Perovskite/Silicon Tandem Solar Cells

Crystalline silicon solar cells have long dominated the global photovoltaic market due to their mature manufacturing processes, excellent stability, and abundant raw material reserves, accounting for over 90% of the total PV market share. However, single-junction c-Si solar cells are approaching the Shockley-Queisser (SQ) efficiency limit of ~29.4%, creating an urgent need for next-generation PV technologies to achieve higher power conversion efficiency (PCE). Monolithic perovskite/silicon tandem solar cells (PSTSCs) stand as the most commercially promising technology to surpass the single-junction efficiency limit. Since their first demonstration in 2015, PSTSCs have experienced rapid technological advancement, with the certified PCE reaching 35.0% in 2026. This review posits that their rapid efficiency ascent is not serendipitous but driven by synergistic innovations across critical subsystems. We systematically deconstruct these efficiency drivers, encompassing top-cell materials, bottom-cell architecture, and optical management. We conclude by outlining future research frontiers essential for transforming this lab-champion technology into a mainstream energy solution.