提高单层GeSe对H_(2)O气体传感性能的第一性原理研究

First-principles study on improving the sensing performance of monolayer GeSe for H_(2)O molecules

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H_(2)O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H_(2)O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H_(2)O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.

Effective methods to improve the sensing performance of monolayer GeSe for H_(2)O 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 H_(2)O adsorbed monolayer GeSe,which would be helpful to improve the sensitivity of the monolayer GeSe to H_(2)O molecules.Especially,under the electric field of-1.0 V/,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 H_(2)O 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.