Chemical inhibition of light-induced decomposition by hindered amine for efficient and stable perovskite solar cells

Despite significant advancements in improving the power-conversion efficiency (PCE) of exceeding 27% in perovskite solar cells (PSCs), the insufficient operational stability of PSCs under illumination remains a critical challenge, posing a major obstacle to their commercial viability. This paper proposes a feasible hindered amine stabilization strategy (HASS) by using a hindered amine light stabilizer for grain and surface modulation of perovskite, thereby blocking the internal and external degradation pathways of perovskite. Its piperidine ring is easily oxidized to form Nitrogen monoxide (N–O•) radicals after absorbing light energy in an aerobic environment. The free superoxide radical (O 2 • − ) radicals react with perovskite and H + in the decomposition products of perovskite, thereby improving the light stability of the device. In addition, the contained triazine and morpholine functional groups can coordinate with Pb 2+ , thereby reducing the interface defects and inhibiting the non-radiative recombination. The HASS-modulated PSC could reach the champion PCE of 26.74% (certified 26.56%), which is remarkable for inverted PSCs prepared under ambient conditions. Further, the unencapsulated device could maintain 95.4% of its initial PCE after more than 1000 hours of aging at maximum power point tracking. • Hindered amine scavenges O2•⁻, suppressing photo-induced perovskite degradation effectively. • Dual-function HASS improves film morphology and passivates Pb2+/I- surface defects. • Achieves 26.74% PCE with 1000-hour light stability under ambient, unencapsulated conditions.