Chaurasiya Rajneesh, Dixit Ambesh
Department of Physics and Center for Solar Energy, Indian Institute of Technology, Jodhpur, 342037, India.
Phys Chem Chem Phys. 2020 Jul 1;22(25):13903-13922. doi: 10.1039/d0cp02063j.
We demonstrated ultrahigh sensitivity with excellent recovery time for H2S, NH3, NO2, and NO molecules on the sulfur and selenium surfaces of Janus WSSe monolayers using density functional theory. The selenium surface of the WSSe monolayer showed strong adsorption in comparison to the sulfur surface. The respective adsorption energies for H2S, NH3, NO2 and NO molecules are -0.193 eV, -0.220 eV, -0.276 eV, and -0.189 eV. These values are higher than the experimentally reported values for ultrahigh sensitivity gas sensors based on MoS2, MoSe2, WS2, and WSe2 monolayers. The computed adsorption energy and recovery time suggest that the desorption of gas molecules can be achieved easily in the WSSe monolayer. Further, the probable vacancy defects SV, SeV, and (S/Se)V and antisite defects SSe, and SeS are considered to understand their impact on the adsorption properties with respect to the pristine WSSe monolayer. We observed that the defect-including WSSe monolayers showed enhanced adsorption energy with fast recovery, which makes the Janus WSSe monolayer an excellent material for nanoscale gas sensors with ultrahigh sensitivity and excellent recovery time.
我们使用密度泛函理论证明了在Janus WSSe单层的硫和硒表面上，对H2S、NH3、NO2和NO分子具有超高灵敏度和出色的恢复时间。与硫表面相比，WSSe单层的硒表面表现出强烈的吸附作用。H2S、NH3、NO2和NO分子各自的吸附能分别为-0.193 eV、-0.220 eV、-0.276 eV和-0.189 eV。这些值高于基于MoS2、MoSe2、WS2和WSe2单层的超高灵敏度气体传感器的实验报道值。计算得到的吸附能和恢复时间表明，气体分子在WSSe单层中能够轻松实现解吸。此外，考虑了可能的空位缺陷SV、SeV和(S/Se)V以及反位缺陷SSe和SeS，以了解它们对相对于原始WSSe单层的吸附性能的影响。我们观察到，包含缺陷的WSSe单层表现出增强的吸附能和快速恢复能力，这使得Janus WSSe单层成为具有超高灵敏度和出色恢复时间的纳米级气体传感器的优异材料。
