Hybrid 2D nanodevices (graphene/h-BN): selecting NOx gas through the device interface

Abstract

Recent experiments demonstrated a highly controlled synthesis of in-plane graphene/hexagonal boron nitride heterostructures, thereby paving the way for the development of a new category of hybrid 2D nanodevices with different interfaces. Herein, by employing a combination of density functional theory (DFT) and the non-equilibrium Green's function formalism (NEGF), the gas sensor capability of G-hBN, containing two different interfaces is assessed by exposing it to NO, NO₂, NH₃, and CO₂ gas molecules. Our results show that the strongest interaction occurs between NO_x molecules and G-hBN; meanwhile, NO and NO₂ molecules are more reactive in the interface regions than the pristine ones. In addition, the electron transport properties reveal that for a distinct two-port voltage applied, the gas molecule NO (NO₂) can be detected by large changes in the conductance and CO₂(NH₃) has insignificant signal conductance, leading to selectivity for the gas. The proposed device is a great potential candidate to be applied as a NO_x gas selector through a 2D nanodevice interface.