Sensing behavior of pentagonal two-dimensional noble-metal dichalcogenide PdSeS for NO2 gas: DFT and semiclassical studies

Abstract

The gas sensing performance of the pentagonal two-dimensional noble-metal dichalcogenide PdSeS for NO2 gas detection has been extensively studied using DFT, the nudged elastic band (NEB) model, and the semiclassical Boltzmann theory. The NEB calculations indicate a highly effective physical NO2 adsorption, implying the potential of the PdSeS monolayer as an excellent material for creating efficient and reusable gas sensors. Additionally, the PdSeS monolayer, characterized as a semiconductor with a band gap of 1.34 eV, demonstrates the emergence of a deep trap in the band structure following the adsorption of NO2 gas. Subsequently, the values of σxx and σyy decrease significantly from 11.41 and 42.82 S/cm to 2.24 and 0.99 S/cm, respectively. The decrease in conductivity can be attributed to several factors, including an increase in effective mass, the formation of deep traps, and a reduction in the number of charge carriers. Furthermore, our calculations demonstrate the potential use of the PdSeS monolayer in work function (WF) type sensors. Consequently, the pentagonal two-dimensional PdSeS monolayer fulfills the demands of portable, affordable, and reusable NO2 gas sensors by exhibiting remarkable sensitivity and short recovery time.