PbSnS₂-Based Gas Sensor to Detect SF₆ Decompositions: DFT and NEGF Calculations

The gas-sensing performance of PbSnS
₂
monolayer to sulfur hexafluoride (SF
₆
) decompositions (SO
₂
, H
₂
S, HF, SOF
₂
, and SO
₂
F
₂
) has been systematically studied by density functional theory and nonequilibrium Green’s function calculations. The most stable adsorption configurations, adsorption energies, charge transfer, electron localization function (ELF), density of states (DOS), and
${I}$
–
${V}$
curves of gas molecules on PbSnS
₂
are calculated and discussed. SO
₂
exhibits the largest adsorption energy of −0.74 eV with the charge transfer of −0.39 e and HF possesses the biggest charge transfer of −0.66 e with the adsorption energy of −0.46 eV. The results of ELF and DOS show that the interaction between SO
₂
and PbSnS
₂
may be stronger than those of other gases. Moreover,
${I}$
–
${V}$
curves show that the responses of PbSnS
₂
to SO
₂
is up to 65.5% at the bias of 2.2 V. Therefore, PbSnS
₂
monolayer may be a qualified material for detecting SF
₆
decompositions.