Density Functional Theory Provides Insights into β-SnSe Monolayers as a Highly Sensitive and Recoverable Ozone Sensing Material

This study explores the potential of beta-SnSe monolayers as a promising material for ozone (O3) sensing using density functional theory (DFT) combined with the non-equilibrium Green's function (NEGF) method. The adsorption characteristics of O3 molecules on the beta-SnSe monolayer surface were thoroughly investigated, including adsorption energy, band structure, density of states (DOSs), differential charge density, and Bader charge analysis. Post-adsorption, hybridization energy levels were introduced into the system, leading to a reduced band gap and increased electrical conductivity. A robust charge exchange between O3 and the beta-SnSe monolayer was observed, indicative of chemisorption. Recovery time calculations also revealed that the beta-SnSe monolayer could be reused after O3 adsorption. The sensitivity of the beta-SnSe monolayer to O3 was quantitatively evaluated through current-voltage characteristic simulations, revealing an extraordinary sensitivity of 1817.57% at a bias voltage of 1.2 V. This sensitivity surpasses that of other two-dimensional materials such as graphene oxide. This comprehensive investigation demonstrates the exceptional potential of beta-SnSe monolayers as a highly sensitive, recoverable, and environmentally friendly O3 sensing material.