A first-principles study of SOF and SOF adsorption onto PdSe-based monolayers: Favorable sensitivity and selectivity by doping single Cu or Rh atom.

In this first-principles study, we simulate the adsorption of SOF and SOF molecules on the pristine, Cu- and Rh-doped PdSe monolayer, in order to explore their potentials as novel gas sensors for status evaluation of the SF-insulation devices. Single Cu or Rh atom is doped by the replacement of a Se atom within the PdSe surface, with the formation energy of 0.40 and -0.62 eV, respectively. Compared with the weak interactions between the pristine PdSe monolayer and two gas species with little potential for gas sensing application, Cu-PdSe monolayer behaves stronger physisorption and Rh-PdSe monolayer conduct more favorable chemisorption upon two gases. The adsorption characteristic, charge density difference, band structure and density of states of various adsorption configurations are systemically analyzed to understand the gas-surface interactions. Results indicate that Pd-PdSe monolayer, rather than the Cu-doped counterpart, is a promising resistive gas sensor with good sensitivity and selectivity for detection of SOF and SOF. The analysis of work function in gas adsorbed Cu- and Rh-PdSe systems reveals their strong potential for the development of Schottky gas sensors upon two gases with high and tunable sensitivity and specificity. These findings in this work hold significant meanings for typical gas detection to evaluate the operational status of SF-insulated devices. It is hopeful that this work can stimulate more edge-cutting investigations on the PdSe-based gas sensor for application in some other fields.