Photoelectron‐Extractive and Ambient‐Stable CsPbBr<sub>3</sub>@SnO<sub>2</sub> Nanocrystals for High‐Performance Photodetection
Hongbin Xiao, Jintao Fu, Xingzhan Wei, Baiqian Wang, Qingkai Qian, Jianfeng Huang, Ru Li, Zhigang Zang
Abstract
Abstract The severe recombination of carriers and poor stability against moisture environment have limited the application of CsPbX 3 (X = Cl, Br, I) nanocrystals in photodetection. Herein, a large‐scale synthesis of SnO 2 ‐coated CsPbBr 3 NCs (abbreviated to CsPbBr 3 @SnO 2 NCs) has been reported for the first time by combining the water‐triggered transformation of Cs 4 PbBr 6 NCs and the hydrolysis of tin 2‐ethylhexanoate. Owing to the construction of the CsPbBr 3 /SnO 2 heterojunction, the recombination rate of carriers in the CsPbBr 3 @SnO 2 NCs is greatly reduced compared to that of the pristine CsPbBr 3 NCs. The stability against water degradation is also improved due to the protection of the SnO 2 coating. Accordingly, a CsPbBr 3 @SnO 2 ‐graphene hybrid device for high‐performance photodetection is demonstrated. Results show that the responsivity of the device reaches 6.2 10 4 A W −1 at 1 V, which is over 496‐fold of the pristine CsPbBr 3 device. This work not only provides a robust approach for the surface modification of CsPbX 3 NCs but also offers useful guidance on the optoelectronic applications with CsPbX 3 NCs.