High Responsivity Solar-Blind Ultraviolet Photodetector Based on (101)-Oriented SnO<sub>2</sub> Nanosheets
Qiannan Ye, Rihui Yao, Guoping Su, Wei Xu, Zihan Zhang, Cheng Luo, Tian Qiu, Taijiang Liu, Honglong Ning, Junbiao Peng
Abstract
SnO 2 nanosheets show the characteristics of exposure to specific crystal planes and high specific surface area, which have a certain application potential in ultraviolet (UV) photodetectors (PDs). However, the low responsivity limits its further development. The photodetector based on SnO 2 nanosheets with (101) preferred orientation shows high spectral selectivity (R 267 nm /R 365 nm ∼ 1470), a responsivity of 539.6 AW –1, and a detectivity of 1.4 × 10 13 Jones at 267 nm. Density functional theory calculations show that the oxygen vacancy formation energy of the (101) surface is smaller than that of the (110) surface. The absolute value of the adsorption energy of oxygen molecules on the oxygen-deficient (101) surface is smaller than that on the oxygen-deficient (110) surface, indicating that oxygen molecules are more easily adsorbed on the oxygen-deficient (101) surface, resulting in more oxygen molecules participating in the UV response of the PD. The results show that the (101)-oriented SnO 2 nanosheet photodetector is a promising candidate device for highly sensitive solar-blind PDs.