Non-ultrawide bandgap CsPbBr 3 nanosheet for sensitive deep ultraviolet photodetection

作者:Wu, Chun-Yan*; Le, Yu-Xuan; Liang, Li-Yan; Li, Jing-Yue; Liang, Feng-Xia; Chen, Shi-Rong; Yang, Xiao-Ping; Zhou, Yu-Xue; Luo, Lin-Bao
来源:JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 2023, 159: 251-257.
DOI:10.1016/j.jmst.2023.03.032

摘要

In this study, we report the fabrication of a sensitive deep ultraviolet (DUV) photodetector by using CsPbBr3 nanosheets synthesized through confined-space growth at room temperature. The peak pho-toresponse of the device upon illumination blueshifts with decreasing thickness and a 68 nm CsPbBr3 nanosheet based device displays a peak response to 265 nm illumination, showing responsivity and spe-cific detectivity of 85 mA/W and 4.05 x 1011 Jones at 3 V bias, respectively. Theoretical simulation re-veals that the blueshift is associated with the wavelength-dependent absorption coefficient of CsPbBr3 nanosheet: incident light with shorter wavelengths can be absorbed on the superficial surface, while long-wavelength light has a larger penetration depth, leading to dominant DUV absorption in thinner CsPbBr3 nanosheet. This work will shed light on the facile and cost-effective fabrication of DUV photode-tectors from non-ultrawide bandgap (UWBG) all-inorganic perovskite materials.