High-Efficiency and Stable Perovskite Photodetectors with an F4-TCNQ-Modified Interface of NiOx and Perovskite Layers

Nickel oxide (NiOx), a typical p-type semiconductor, is emerging as the most promising hole transport layer material. However, the inferior interfacial contact of the NiOx/perovskite interface has limited the improvement of the performance of photodetectors (PDs). In this work, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) is introduced to modify the NiOx/perovskite interface to prepare high-performance PDs. This study shows that the F4-TCNQ layer interacts with the NiOx/perovskite layers. It can increase the Ni3+/ Ni2+ ratio and then enhance the hole extraction and charge carrier mobility; on the contrary, it can form a new Lewis adduct and passivate the undercoordinated Pb2+ ions. Furthermore, with the F4-TCNQ modification, the perovskite film exhibits good thermal stability and photostability. The PDs demonstrate excellent photoelectric properties and long-term stability in the atmosphere. This finding provides a simple and efficient way to further develop the NiOx/perovskite interface.

Automated summary

In this study, a modifier called F4-TCNQ is introduced to improve the performance of the NiOx/perovskite interface. The modified interface shows enhanced hole extraction, charge carrier mobility, thermal stability, and photostability of the perovskite film, leading to excellent photoelectric properties and long-term stability in photodetectors. This finding provides a simple and efficient approach for further development of the NiOx/perovskite interface.