CsPbBr₃quantum dots assisted crystallization of solution-processed perovskite films with preferential orientation for...

The performance of hybrid perovskite solar cells (PSCs) is significantly influenced by the crystallization and morphology of perovskite films. Herein, a novel method of CsPbBr₃quantum dots (QDs) assisted nucleation is applied to prepare high quality solution-processed methylammonium lead iodide (MAPbI₃) films by employing CsPbBr₃QDs as an additive into diethyl ether anti-solvent. The appropriate amount of CsPbBr₃QDs can act as effective heterogeneous nucleation centers, leading to the formation of smooth and pinhole-free perovskite films with increased grain size. Furthermore, the growth direction of MAPbI₃grains is regulated by CsPbBr₃QDs, exhibiting preferential orientation of (110) plane. Therefore, the MAPbI₃films with CsPbBr₃QDs modification show reduced defects and increased carrier lifetime. As a result, the champion PSC with a maximum power conversion efficiency (PCE) up to 20.17% is achieved and 85% of its initial PCE is maintained after aging 1000 h at room temperature under a relative humidity of 50%. This work demonstrates a feasible way to prepare high quality perovskite films for optoelectronic applications.