Monolayer GeS as a potential candidate for NO2 gas sensors and capturers

Abstract

The gas sensing properties of single-layer GeS have been studied by performing density functional theory (DFT) calculations, and the present results demonstrate that monolayer GeS exhibits high selectivity and sensitivity toward NO₂ molecules and short recovery time, coupled with a strong anisotropic transport feature. Moreover, applying biaxial strains and electric fields could effectively modulate the capture and release of gaseous NO₂. Further calculations indicate that oxygen atoms and water molecules decorated on GeS hardly affect the superb selectivity toward NO₂ against the other gases. The presence of an S-vacancy on the GeS monolayer greatly promotes the adsorption of NO₂, facilitating molecular dissociation. The underlying mechanism is also elaborated at the level of electronic structures. The present findings make GeS monolayers potential materials for NO₂ gas sensors and capturers in future applications.