提高单层GeSe对H2O气体传感性能的第一性原理研究

采用第一性原理计算方法，通过在单层GeSe上施加双轴向应变、外加电场、掺Ag等途径来探索提高单层GeSe对H₂O分子传感性能的有效方法，并从微观角度阐明内在机理.计算结果表明，-1.0 V/?的外加电场能有效降低H₂O分子在单层GeSe的吸附能并使二者之间的电荷转移量增加11倍，显著提高了单层GeSe对H₂O分子的响应速度和敏感性.研究结果为进一步设计并制成二维GeSe基湿度传感器提供了理论依据.

First-principles study on improving the sensing performance of monolayer GeSe for H2O molecules

Effective methods to improve the sensing performance of monolayer GeSe for H2O molecules were explored by applying biaxial strain, external electric field, and Ag-doping through first-principles calculations. The biaxial strain had great effect on the band structure of the adsorption system. Applying a negative external electric field and embedding an Ag atom in the surface Ge vacancy of the substrate monolayer GeSe enhanced the adsorption ability and the charge transfer of the H2O adsorbed monolayer GeSe, which would be helpful to improve the sensitivity of the monolayer GeSe to H2O molecules. Especially, under the electric field of -1.0 V/Å, the amount of the charge transfer is up to 11 times higher than that of the original state, because of the dominance of the interaction between H2O molecular HOMO and the orbital of the surface Ge atom, which greatly enhances the orbital hybridization. The present study would provide theoretical basis for designing and manufacturing of two-dimensional-GeSe-based humidity sensor in the future.