Effect of vacancy defect and dopants on the sensitivity of germanene to H2CO

Abstract

The geometric and electronic structures, magnetism, and recovery time of vacancy-defected and doped germanene, which is used as a sensor for the detection of H 2 CO molecule, are examined using first-principles calculation methods. The results reveal that the introduction of vacancy and transition metal dopants (V, Cr, Mn, Fe) increases the adsorption stability of H 2 CO on germanene. In addition, V-doped vacancy-defected germanene (V-VGe) is converted from semiconductor to conductor by absorbing H 2 CO molecules, which can be used as an obvious signal to detect H 2 CO gas. Furthermore, the strong interaction with H 2 CO and the short recovery time indicates that V-VGe is most sensitive to the H 2 CO molecules. Overall, the findings of this study provide theoretical reference for the design of a new H 2 CO gas sensor. First-principles calculation method based on density functional theory is used to study the effect of vacancy and transition metal dopants (V, Cr, Mn, Fe) on the adsorption of H 2 CO on germanene.The results show that doping effectively improves the sensitivity of the vacancy-defected germanene to H 2 CO molecule. • The appearance of vacancy defects enhances the sensitivity of the germanene substrate. • Doped transition metal atoms (V, Cr, Mn, Fe) can improve the adsorption capacity of vacancy-defective germanene to H 2 CO molecules. • Vacancy-defective germanene doped with V atoms can be used to detect H 2 CO molecules.