A DFT Calculation: Gas Sensitivity of Defect GeSe to Air Decomposition Products (CO, No and NO2)

Based on first-principles calculations, the structures of GeSe monolayer with point defects, including vacancy and the anti-site defects, were initially optimized. Subsequently, the paper studied air discharge decomposition products (CO, NO, and NO 2 ) on defective GeSe. The adsorption behavior, densities of states, projected densities of states, work function, charge transfer, and sensitivity of \text{V}_{\text {Se}} -GeSe and Ge Se -GeSe towards CO, NO, and NO 2 molecules were further analyzed. These analyses indicate that \text{V}_{\text {Se}} -GeSe and Ge Se -GeSe strongly interact with CO, NO, and NO 2 molecules. As a result, both \text{V}_{\text {Se}} -GeSe and Ge Se -GeSe have excellent gas-sensing and selectivity properties to NO, CO, and NO 2 molecules than intrinsic GeSe monolayer. And Ge Se -GeSe is more suitable than \text{V}_{\text {Se}} -GeSe for CO, NO, and NO 2 molecules detection.