Synergistic Defect Healing and Device Encapsulation via Structure Regulation by Silicone Polymer Enables Durable Inverted Perovskite Photovoltaics with High Efficiency

Polymers play a crucial role in promoting the progress of high-performance inverted perovskite solar cells (PSCs). However, few polymers have simultaneously achieved defect passivation and device encapsulation in PSCs. Herein, a telechelic silicone polymer (poly(dimethylsiloxane-co-methylsiloxane acrylate) [PDMA]) is introduced, which possesses crosslinking capability to enable structure regulation through a condensation reaction. By leveraging the advantages of the polymers before and after crosslinking, a synergistic strategy of defect healing and device encapsulation for PSCs is developed via the application of the targeted polymer. PDMA as additives anchors tightly at the grain boundaries (GBs) and bridges the perovskite grains, achieving defect passivation and GBs crosslinking, increasing the efficiency of inverted PSCs from 22.32% to 24.41%. Crosslinked PDMA (CPDMA) is used as an encapsulant to encapsulate the entire device, enabling non-destructive encapsulation at room temperature and inhibiting perovskite degradation under photothermal aging. Remarkably, the PDMA-modified device with CPDMA encapsulation maintains 98% of its initial efficiency after 1200 h under continuous illumination at 55 +/- 5 degrees C and retains 95% of its original efficiency after 1000 h of damp heat testing, meeting one of the IEC61215:2016 standards. This work reports a synergistic strategy of defect healing and device encapsulation for perovskite solar cells via the structure regulation of telechelic silicone polymer (PDMA). PDMA as an additive achieves defect healing, and cross-linked PDMA as an encapsulant achieves non-destructive encapsulation and delays the decomposition of perovskite. The resulting PSCs yield excellent operational stability and damp heat stability with high efficiency.image