Janus PtSTe monolayer as a modulable and outstanding gas sensing buddy

This work implements the first-principles investigation on the adsorbing and sensing performance of PtSTe monolayer towards several toxic gas species, namely NO, NO2, N2O and NH3. The adsorption configurations, electronic properties as well as the sensing potential of the PtSTe monolayer are systemically analyzed. The adsorption strength upon four gases is in order as: NO2 > NO > NH3 > N2O, with the adsorption energy obtained as −0.562, −0.403, −0.292, and −0.212 eV, respectively. The band structure, dielectric function and work function analyses reveal the potential of PtSTe monolayer as resistance-type, optical or Kelvin probe gas sensor upon typical gas species. Besides, the applied biaxial strains can make the PtSTe monolayer be a strain-tunable gas sensors, especially for N2O and NH3, and Non-equilibrium Green's function analysis proves its potential for field-effect transistor gas sensing with desirable electrical response upon four gases. The findings in this work can give the theoretical guidance for exploration of novel 2D gas sensing materials and are meaningful to stimulate more edge-cutting research in this field.