High Performance Perovskite Solar Cells by Perovskites Co-Crystallized with Polymers

Extensive interest has been raised by perovskite materials as emerging alternatives for low-cost and efficient perovskite solar cells (PSCs) in the past decade. However, achieving high-performance and stable PSCs with negligible photocurrent hysteresis behavior is still a challenging task due to the intrinsic foibles of perovskites. In this work, we report efficient and stable PSCs with dramatically suppressed photocurrent hysteresis by CH3NH3PbI3 co-crystallized with poly(ethylene oxide) (PEO). It is found that PEO-CH3NH3PbI3 thin film exhibit superior film morphology and significantly enlarged crystal grains as compared with CH3NH3PbI3 thin film. Systematical investigations reveal that the introduction of PEO in CH3NH3PbI3 could improve the charge transport and reduce the charge carrier recombination and promote the charge carrier extraction time within PSCs. As a result, PSCs by PEO-CH3NH3PbI3 thin film exhibit a power convention efficiency of 20.73%, which is over 20% enhancement as compared with that (17.42%) from PSCs by CH3NH3PbI3 thin film. Moreover, photocurrent hysteresis is dramatically suppressed in PSCs by PEO-CH3NH3PbI3 thin film. In addition, PSCs by PEO-CH3NH3PbI3 thin film exhibit boosted stability. All these results demonstrate that perovskites co-crystallized with polymers is an efficient approach towards high performance PSCs.