Development of SiC monolayer for detection of SO3 and NF3 hazardous gases based on DFT calculations

Abstract

Identifying intrinsically selective materials towards gas molecules can dramatically simplify designing selective and sensitive sensors in order to detect these gasses. Researchers have recently explored monolayers with group III–IV elements as encouraging materials for sensing various gasses. Within this piece of research, we undertook first-principles DFT computations for exploring the gas adhesion attributes of a silicon carbide monolayer (SiCML). The adhesion energies, adhesion distances, adhesion nature and strength as well as the charge transports were examined. The changes in workfunction and conductance were also computed to analyze their prospects in electronic- and workfunction-based gas sensor applications. For this purpose, the adhesion of NF₃, H₂S, CO, SO₃ and CO₂ was investigated, and it was found that the SiCML was sensitive to these gasses, especially SO₃ and NF₃ had a chemical adhesion with adsorption energy −0.56 and −0.75 eV, respectively. Also, the workfunction value of SiCML were changed about 18.39 % and 17.94 % after SO₃ and NF₃, respectively. In addition, NF₃ adsorption changed the band gap of SiCML from 2.29 to 0.38 eV. Furthermore, the recovery time for NF₃ at 600 K is about 4.48 s, which showed the sensitive and selective response of NF₃ in the SiCML.