Topological insulator Bi2Se3 for highly sensitive, selective and anti-humidity gas sensors
Bingsheng Du, Wei Kang, Yong He, Yan Wang, Xi Yang, Gang Meng, Zetao Zhu, Xiaohui Lin, Yiling Tan, Chengyao Liang, Xuezheng Guo, Jikang Jian, Yongcai Guo, Miao Zhou
Abstract
Chemiresistive gas sensors generally surfer from low selectivity, inferior anti-humidity, low response signal or signal-to-noise ratio, severely limiting the precise detection of chemical agents. Herein, we exploit high-performance gas sensors based on topological insulator Bi 2 Se 3 that is distinguished from conventional materials by robust metallic surface states protected by time-reversal symmetry. In the presence of Se vacancies, Bi 2 Se 3 nanosheets exhibit excellent gas sensing capability toward NO 2 , with a high response of 93% for 50 ppm and an ultralow theoretical limit of detection concentration about 0.06 ppb at room temperature. Remarkably, Bi 2 Se 3 demonstrates ultrahigh anti-humidity interference characteristics, as the response with standard deviation of only 3.63% can be achieved in relative humidity range of 0–80%. These findings are supported by first-principles calculations, with analyses on adsorption energy and charge transfer directly revealing the anti-humidity and selectivity. This work may pave the way for implementation of exotic quantum states for intelligent applications.