Surface Chelation Enabled by Polymer-Doping for Self-Healable Perovskite Solar Cells

Polymer doping is an efficient approach to achieve self-healing perovskite solar cells. However, achieving high self-healing efficiency under moderate conditions remains challenging. Herein, an innovative self-healable polysiloxane (PAT) containing plenty of thiourea hydrogen bonds was designed and introduced into perovskite films. Abundant thiourea hydrogen bonds in PAT facilitated the self-healing of cracks at grain boundaries for damaged SPSCs. Importantly, the doped SPSCs demonstrated a champion efficiency of 19.58% with little hysteresis, almost rivalling those achieved in control atmosphere. Additionally, owing to the effective chelation by PAT and good level of thiourea hydrogen bonds, after 800 cycles of stretching, releasing and self-healing, the doped SPSCs retained 85% of their original IPCE. The self-healing characteristics were demonstrated in situ after stretching at 20% strain for 200 cycles. This strategy of pyridine-based supramolecular doping in SPSCs paves a promising way for achieving efficient and self-healable crystalline semiconductors.