Influence of defects and dopants on the sensitivity of arsenene towards HCN

Abstract The geometrics, electronic structures and magnetism of defected and doped arsenene were investigated as sensors to detect HCN molecules through the density functional theory (DFT). The results indicated that HCN molecules are physically adsorbed onto Stone-Wales (SW) and vacancy defected arsenene, in a manner comparable to perfect arsenene. Following the introduction of dopants (Ti, V, Cr and Ni), the interaction between HCN and doped arsenene was effectively enhanced, and the adsorption transformed to chemisorptions. Furthermore, the V- and Ni-doped arsenene changed from conductors to semiconductors through adsorption of HCN molecule, which could be treated as obvious electrical signals to detect HCN gas. Our calculations suggest that doping is more effective than defects to improve the sensitivity of arsenene to HCN gas. This provides a theoretical basis for their application as sensors based on arsenene.