In situ formation of a low-dimensional perovskite structure for efficient single-crystal MAPbI3 solar cells with enhanced ambient stability†

Abstract

Metal halide perovskite solar cells (PSCs) have rapidly advanced in recent years, with the power conversion efficiency surpassing that of silicon solar cells. Even though perovskite single-crystal films possess superior properties due to the absence of grain boundaries, they still present numerous surface defects which serve as non-radiative recombination centers. Therefore, passivating surface defects is crucial for optimizing the performance of single-crystal PSCs (SC PSCs). In this study, the functional molecule 2-phenylethylamine hydroiodide (PEAI) constructing a low-dimensional structure is used for this purpose. The introduction of PEAI enhances the perovskite surface properties by reducing dangling bonds and lowering defect density. As a result, it facilitates charge carrier transport at the interface between the perovskite layer and the charge transport layer. With the influence of PEAI, the efficiency of MAPbI₃ SC PSCs enhances from 19.71% to 21.2% and the air stability also increases. This work provides a feasible and effective strategy to improve the efficiency and stability of SC PSCs.