An innovative design of perovskite solar cells with Al 2 O 3 inserting at ZnO/perovskite interface for improving the performance and stability

A novel perovskite solar cell (PSC) structure with high efficiency is designed through separating the ZnO electron transport layer and perovskite layer by an ultra-thin Al2O3 insulating layer. The application of insulating layer can effectively decline the degradation rate of perovskite. In addition, the thickness of the insulating layer is optimized by a quantum tunneling model based on effective-mass approximation (EMA) theory. The performance of the PSCs could be modulated by tuning the thickness of Al2O3 middle layer, and the experimental results are consistent with theoretical results. The optimal insulating layer has a capability to suppress the carriers recombination process and improve the conversion efficiency of PSCs. The highest conversion efficiency of optimized PSC is 15.55% at the thickness of 4 Å. Therefore, the interface modulation protocol of inserting Al2O3 insulating layer at ZnO/perovskite interface provides a promising approach for novel design of PSCs with commercial values.