Isopropylammonium doping enhances efficiency and stability of triple-cation perovskite solar cells via effective intrinsic lattice modulation

Despite remarkable advances in efficiency, perovskite solar cells (PSCs) still suffer from critical stability issues arising from halide vacancies and ion migration induced by intrinsic lattice defects. Herein, an effective doping strategy to enhance intrinsic stability is introduced. Guided by density functional theory calculations, isopropylammonium (IPA⁺) is identified and incorporated into the perovskite lattice. IPA doping effectively reduces bulk defects and suppresses non-radiative recombination, while simultaneously disrupting ion migration pathways and inhibiting ion migration. As a result, the IPA-doped device achieves a power conversion efficiency (PCE) of 23.3 % and an open-circuit voltage of 1.214 V, ranking among the highest reported for single-junction PSCs with a bandgap of ∼1.63 eV. Moreover, the doped devices exhibit exceptional stability, retaining over 96 % of their initial PCE after 960 h of dark storage (ISOS-D-1), over 94 % after 288 h of thermal aging at 65 ℃ (ISOS-D-2), about 93 % after 288 h of thermal cycling, and 74 % after 288 h of continuous light soaking (ISOS-L-1). This study highlights the synergy between computational prediction and experimental validation, offering a new compositional design strategy for intrinsically stabilizing perovskite materials.