Pd-doped PtSe2 monolayer with strain-modulated effect for sensing SF6 decomposed species: a first-principles study

This work employing the first-principles theory investigated the potential of Pd-doped PtSe2 (Pd–PtSe2) monolayer as a sensing material for detection of H2S and SOF2 in the SF6 insulation devices. The Pd dopant is stably trapped on the TPt site of the PtSe2 surface with Eb of −2.37 eV, and the bandgap of Pd–PtSe2 system is reduced to 0.81 eV from that of 1.31 eV of the pristine counterpart. Pd–PtSe2 monolayer has stronger adsorption performance upon SOF2 with Ead of −0.94 eV than H2S with Ead of −0.88 eV, leading to more obvious increase to 0.96 eV in the SOF2 system than that of 0.84 eV in the H2S system. Thus, the much higher sensitivity and more desirable recovery property give rise to the stronger suitability of Pd–PtSe2 monolayer for SOF2 detection, as verified by the I–V curve analysis wherein the electrical resistance and sensing response are seen much larger in the SOF2 system. Moreover, the applied strain is proved as a workable manner to modulate the sensing performance of Pd–PtSe2 monolayer, with tunable QT and Eg obtained in various strains. Our calculations evidence the potential of Pd–PtSe2 monolayer as a promising gas sensor to evaluate the operation status of the SF6 insulation devices, which is beneficial to stimulate more edge-cutting work in the field of gas sensing as well.