Electronic, mechanical and gas sensing properties of two-dimensional γ-SnSe

• Published in: Physical chemistry chemical physics : PCCP Vol. 25; no. 42; pp. 28716 - 28726
• Main Authors: Zhu, Chunyan, Feng, Tianhang, Jiang, Xinying, Li, Gang, Yuan, Jun-Hui, Liu, Chao, Zhang, Pan, Wang, Jiafu
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.11.2023
• Subjects: Adsorption; Ammonia; Anisotropy; Carbon dioxide; Charge transfer; Energy gap; First principles; Flexible components; Gas sensors; Gases; Interlayers; Mechanical analysis; Mechanical properties; Monolayers; Multilayers; Nitrogen dioxide; Nitrogen oxides; Poisson's ratio; Sensitivity enhancement; Sulfur dioxide; Two dimensional materials
• DOI: 10.1039/d3cp03483f
• ISSN: 1463-9076; 1463-9084

Two-dimensional (2D) materials are excellent candidates for advanced flexible electronics and gas sensors. Herein, we systematically investigate the layer-dependent electronic structures, mechanical properties and gas sensing characteristics of the newly synthesized γ-SnSe based on first-principles calculations. Bulk γ-SnSe is a typical van der Waals layered material with an indirect narrow band gap, while monolayer and multilayer γ-SnSe can be obtained through mechanical exfoliation due to its low cleavage energy. The band gap of γ-SnSe gradually increases with decreasing layers, reaching a value of 2.25 eV for the monolayer due to weakened interlayer coupling. Mechanical analysis reveals strong anisotropy in multilayer γ-SnSe, whereas the monolayer exhibits a negative Poisson's ratio (−0.023/−0.025). Additionally, based on the analysis of electronic structures, adsorption energies and charge transfer of the host materials after adsorption of various gases, it is found that the γ-SnSe monolayer demonstrates enhanced sensitivity and selectivity towards NO, NO 2 , and SO 2 compared to CO, CO 2 , H 2 S and NH 3 . These findings highlight the potential of γ-SnSe as an excellent gas-sensitive material for the detection of nitrogen oxides and sulfur dioxide. Two-dimensional (2D) materials are excellent candidates for advanced flexible electronics and gas sensors.