The interface defects of perovskite (PVK) thin films are the main factors that lead to the instability of PVK solar cells (PSCs) and the low photoelectric conversion efficiency (PCE). Li Mingzhu, et al., Institute of chemistry, Chinese Academy of Sciences, used SnO2 mxene composite electron transport layer (ETL) for PSC to improve interface contact and passivate defects at SnO2 / perovskite interface.
The introduced mxene regulates SnO2 dispersion and induces PVK vertical growth. The lattice matching of mxene and perovskite suppresses the concentration of interfacial stress, thereby obtaining Perovskite Thin Films with low defects. Compared with SnO2 based devices, the PCE of SnO2 mxene based devices is improved by 15%, the short-circuit current is as high as 25.07 Ma cm-2, and the efficiency is up to 23%.
In addition, even after 500 hours of storage under the condition that the relative humidity in the ambient air is 30-40%, the unpacked device still maintains about 90% of its initial efficiency. The composite ETL strategy provides a way to design the interface passivation between metal halide perovskite and ETL.
Wu, C., Fang, W., Cheng, Q., Wan, J., Wen, R., Wang, Y., Song, Y. and Li, M. (2022), MXene-Regulated Perovskite Vertical Growth for High-Performance Solar Cells. Angew. Chem. Int. Ed..
https://doi.org/10.1002/anie.202210970
