A first-principles study: Adsorption of small gas molecules on GeP3 monolayer
A first-principles study: Adsorption of small gas molecules on GeP3 monolayer
复制标题
第一性原理研究：小气体分子在 GeP3 单层上的吸附
DOI：
10.1016/j.susc.2019.02.008
复制
发表时间：
2019-06-01
期刊：
影响因子：
1.9
通讯作者：
Yang Daoguo
中科院分区：
文献类型：
--
作者：
Niu Fanfan;Cai Miao;Yang Daoguo
利用第一性原理计算，我们研究了小气体分子（H2O、CO2、CH4、SO2、H2S和NH3）在GeP3单层上的吸附效果。为了确定最稳定的吸附位点，本文考虑了5个吸附位点（中心、Ge、P、桥Ge-P和桥P-P）。通过计算吸附能、吸附距离和电荷转移，我们初步确定H2O、CO2和CH4是通过弱范德华力在GeP3上进行物理吸附的。而通过电子定位函数和电荷密度差的计算可知，SO2、H2S和NH3在GeP3上被化学吸附，形成了新的共价键。气体分子吸附可以引起单层GeP3带隙的显著变化，表明原始的GeP3单层对这些气体敏感。此外，外加电场可以有效调节GeP3吸附的H2O、CO2和CH4的吸附能。我们的理论研究表明，GeP3单层膜是一种很有前途的用于纳米器件的气敏材料。
Using first-principles calculation, we have studied the adsorption effect of small gas molecules (H2O, CO2, CH4, SO2, H2S, and NH3) on GeP3 monolayer. To determine the most stable adsorption site, five adsorption sites (center, Ge, P, bridge Ge-P, and bridge P-P) were considered in the paper. Through calculations of adsorption energy, adsorption distance, and charge transfer, we preliminarily determined that H2O, CO2, and CH4 were physically adsorbed on GeP3 via weak van der Waals force. However, SO2, H2S, and NH3 were chemically adsorbed on GeP3 with new covalent bonds formed, as concluded by calculations of electron localization function and charge density difference. Gas molecule adsorption can cause significant changes in the band gap of single-layer GeP3, indicating that pristine GeP3 monolayer is sensitive to these gases. In addition, the adsorption energy of the H2O, CO2, and CH4 adsorbed on GeP3 can be tuned effectively by employing an external electric field. Our theoretical studies reveal that GeP3 monolayer is a promising gas-sensitive material used in nanometer devices.