Computational Study of Borophene with Line Defects as Sensors for Nitrogen-Containing Gas Molecules

Borophene, a member of two-dimensional (2D) materials, has very important application potential in gas sensing because of its large surface area and rich electronic properties. Very recently, the intrinsic line defects in β12 and χ3 borophenes have been observed experimentally. In this work, by means of density functional theory computations coupled with the nonequilibrium Green’s function (NEGF) method, we explored the potential applications of 2D borophene with two different kinds of line defects in gas sensing. It is found that the nitrogen-containing gas molecules such as NO, NO2, and NH3 can be strongly adsorbed on the line defects of borophene with considerably high adsorption energies. Remarkably, according to the transmission coefficient and I–V characteristics, the adsorption of these nitrogen-containing gas molecules can induce significant change in the current of defective borophene even at rather low biases. Especially, the degree of current change strongly depends on the type of adsorbed molecules. The extraordinary sensitivity and selectivity suggest that it is possible to design nitrogen-containing gas sensors based on borophene with line defects.