Zn2+ modification for enhancing performance of CsPbBr3 perovskite solar cells

Zn 2+ modification optimizes CsPbBr 3 crystallization, producing pinhole-free films with enlarged grains. • Optimized films show enhanced light absorption and suppressed non-radiative recombination losses. • 0.5% Zn 2+ -modified devices achieve a champion PCE of 8.54%, a 21% gain over controls. • Unencapsulated devices retain 91.6% of initial PCE after 720 h at 80 °C/80% RH. Although CsPbBr 3 perovskite solar cells (PSCs) exhibit excellent environmental stability, their wide bandgap and high defect density limit further improvement in power conversion efficiency (PCE). This study introduced Zn 2+ modification strategy to optimize the performance of perovskite. Resulting in a denser morphology, increased grain size and improved crystallinity of the CsPbBr 3 film. Such microstructural optimization significantly enhanced light absorption and effectively suppressed non-radiative recombination. Consequently, the 0.5% Zn 2+ -modified device achieved a champion PCE of 8.54%, representing a significant enhancement over the 7.07% efficiency of the unmodified device. Moreover, the unencapsulated device demonstrates excellent stability, retaining over 91.6% of its initial efficiency after 720 h of storage at 80 °C and 80% relative humidity. This work demonstrates that Zn 2+ modification is an effective strategy for optimizing the crystallization of CsPbBr 3 film and improving the efficiency of PSCs, offering a practical route toward low-cost, stable CsPbBr 3 photovoltaic devices.