Gas Sensing Properties of Defective Tellurene on the Nitrogen Oxides: A First-principles Study

Abstract As the first two dimensional (2D) mono-elemental material of group-VI, tellurene is expected to be a promising gas sensor over the state-of-the-art 2D materials. Based on the density functional theory (DFT) calculation, we mainly focused on improving the adsorption and sensing properties of the tellurene to the nitrogen oxide molecules (NOX) via defect engineering. Three point defects in the tellurene, such as Stone-Wales defect, single vacancy-1 and single vacancy-2, were extensively investigated due to their lower thermodynamic energies. Compared with the pristine tellurene, these defects can enhance the adsorption strength of NOX on the tellurene with the electronic band structures as well as the electronic transport properties (e.g, current-voltage curves, equilibrium transmission spectra) altering sensitively. The changes near the Fermi level of the density of states (DOS) are mainly attributed to the p orbit of N, O and Te atoms. This study can extend the gas sensor family for the nitrogen oxides by providing theoretic reference for the rational design in the experiments.