Strategies Toward Maximizing Power Conversion Efficiency in All‐Perovskite Tandem Solar Cells

Perovskite/silicon tandem solar cells have achieved certified efficiencies approaching 35%, but further progress is constrained by the fixed silicon bandgap, current‐matching instability, and mechanical rigidity. All‐perovskite tandem solar cells (APTSCs) provide a promising route to overcome these limitations through tunable bandgaps, compositional flexibility, and low‐temperature processing. In particular, triple‐junction (3J) APTSCs show the potential to surpass 40% efficiency by stacking wide‐, intermediate‐, and narrow‐bandgap (WBG, IBG, NBG) subcells with complementary spectral utilization. This review summarizes recent advances toward stable and efficient 3J APTSCs, including halide homogenization and additive‐assisted crystallization for WBG absorbers, oxidation control and interface passivation for NBG subcells, and key considerations for IBG subcells, particularly the need for thermally stable surface passivation. In addition, we discuss the critical role of optoelectronic modeling at the 3J device level for managing parasitic optical losses and achieving accurate current matching across multilayer stacks. Collectively, these developments underscore the technological potential of all‐perovskite 3J tandems as a scalable and sustainable platform for next‐generation photovoltaics.