Minimizing the transport loss and degradation of perovskite optoelectronics via grain dimerization technique

Abstract As a next‐generation photovoltaic device, perovskite solar cell (PSC) is rapidly emerging by its appealing properties. Nevertheless, owing to the degradation which is initiated from the grain boundaries and dangling bonds on the surface, PSC is struggling with not only power conversion efficiency (PCE) but its stability. Herein, dimerization technique using diphenyl(4‐vinylphenyl)phosphine (DVP) is suggested to heal both bulk and interfaces of the perovskite grains. Effective DVP dimerization results in the minimized‐defect perovskite and constructs strong cross‐linking networks inside the grains, enabling improved device performance, reproducibility and stability. Furthermore, hydrophobic species of DVP boost the stability against humidity, which is confirmed by the solar cell dipped in water. As a result, this work obtained PSCs with improved film morphology, reproducibility and stability by DVP dimerization, achieving 21.1% of PCE stable for 1000 h under extreme conditions (AM 1.5G and 60°C, encapsulated). image