Poly(Ethylene Glycol) Diacrylate as the Passivation Layer for High-Performance Perovskite Solar Cells

In the past decade, greatest effect has been paid on organic-inorganic halide perovskites for approaching high-performance perovskite solar cells (PSCs). It was found that severe surface-defect within the perovskite active layer restricted further boosting device performance of PSCs. Here, we report high-performance PSCs by utilization of an ultrathin solution-processed poly(ethylene glycol) diacrylate (PEGDA) layer to passivate the surface-defect within the perovskite thin film. Systematical studies demonstrate that the PEGDA-passivated perovskite thin film exhibit suppressed nonradiative recombination and trap density, as well as superior film morphology with a smoother surface, larger crystal size, and better crystallinity. Moreover, PSCs by the PEGDA-passivated perovskite thin film exhibit suppressed charge carrier recombination, reduced charge-transfer resistance, shorter charge carrier extraction time, and enlarged built-in potential. As a result, PSCs by the PEGDA-passivated perovskite thin film show a power conversion efficiency of over 21% and a photocurrent hysteresis index of 0.037. Moreover, unencapsulated PSCs by the PEGDA-passivated perovskite thin film possess over 10 day operational stability. All these results indicate that our approach provided a facile way to boost device performance of PSCs.