Minimizing Voltage Losses in Perovskite Solar Cells

Organic–inorganic metal halide perovskite solar cells (PSCs) have achieved an unprecedented increase in power conversion efficiency (PCE) from 3.8% to 25.2% in the past decade. Given that the open‐circuit voltage (V_oc) of PSCs is well below its theoretical limit due to the trap‐mediated charge recombination and energy band alignment mismatch, there is still considerable scope to further increase the PCE by minimizing V_oc losses. Herein, a fundamental understanding on the origins of voltage losses in PSCs is summarized. Then, the strategies for mitigating the voltage losses of PSCs are critically reviewed, including crystal growth control, grain‐boundary defect passivation, interfacial defect passivation, and band alignment optimization. Finally, the current challenges are discussed and the future directions are outlined to further boost the V_oc of PSCs toward their radiative limit.