MgAc<sub>2</sub>-Modified SnO<sub>2</sub> Electron Transport Layer for Highly Efficient and Thermal Stable Perovskite Solar Cells
Mina Guli, YuJing Zhang, Ran Li, Wenkai He, Cheng Lan, Yancheng Zhou
Abstract
There are always defects and oxygen vacancies in SnO 2 prepared by solution methods, hindering efficient carrier transfer between SnO 2 and the perovskite in perovskite solar cells. Thus, we employed MgAc 2 to modify the interface. Carboxyl groups of MgAc 2 filled the oxygen vacancies in SnO 2, reducing its surface defect density, and Mg 2+ partially replaced surface Sn 4+, improving the properties of the SnO 2 layer. Finally, perovskite solar cells modified with MgAc 2 exhibited a significant improvement in open-circuit voltage and fill factor, improving the power conversion efficiency from 20.52% to 22.02%. Moreover, MgAc 2 -devices maintained 80% of the initial efficiency after 1250 h in thermal stability tests at 85 °C and 30% relative humidity compared to control devices. This work provides a method for treating the SnO 2 electron transport layer and demonstrates the synergistic effects of Mg 2+ and acetate ions, which can facilitate the development of efficient and stable perovskite solar cells.