Sustainable protection of natural liquid enables ultra-stable inverted perovskite solar cells via allylic disulfide rearrangement

Perovskite solar cells (PSCs) suffer from instability under prolonged exposure to light, moisture, and heat, primarily due to uncoordinated ionic defects. Current strategies primarily focus on using solid-state molecules to repair defect sites. However, the accumulation of these solid-state molecules at grain boundaries and surfaces further compromises the long-term stability of efficient PSCs. Here, we develop a natural liquid waterproof agent, diallyl disulfide (DAD), as an additive to regulate perovskite crystallization by chemical rearrangement, thereby stabilizing the phase structure to improve the device durability and passivating defects to regulate the interface energy level. Additionally, DAD molecules sustainably passivate defects and form an oily barrier to protect perovskites from external stresses. DAD-based PSCs achieved a power conversion efficiency (PCE) of 26.08% (certificated 25.72%) with exceptional stabilities. Unencapsulated devices retained 91.6% of their initial PCEs after 2200 h of continuous light soaking, 90.5% efficiency under 85 °C heat condition for 1200 h, and 98.5% efficiency after 12 light-dark cycling tests. And the inverted modules provide an impressive PCE of 20.98% with an aperture area of 26.78 cm². Notably, the module maintained over 90% of its initial efficiency after continuous 600 h of 1-sun illumination.