Homogenizing inter-grain recombination stabilizes perovskite solar cells

Perovskite solar cells (PSCs) have achieved remarkable efficiencies, but operational stability remains a key challenge. This highlight discusses the work of Zhang et al., who identify asymmetric inter-grain recombination at heterogeneous grain boundaries as a previously overlooked degradation pathway. By homogenizing inter-grain recombination through selective grain-boundary passivation, they simultaneously improve efficiency and stability. This work establishes carrier equilibrium across neighboring grains as a new design principle for developing durable, high-performance PSCs.