Structural, electronic and optical properties of anisotropic AlN/BP van der Waals heterostructures with high carrier mobility and remarkable optical absorption

Abstract

The structural, electronic and optical properties of van der Waals heterostructures (vdWHs) of AlN/BP 2D layers have been investigated. Using density functional theory (DFT) calculations, six distinct vertical arrangements of insulating plates composed of aluminum nitride (AlN) and boron phosphide (BP) examined. All six AlN/BP-XX (XX = AA, BB, CC, DD, EE, FF) heterostructures exhibit direct bandgap behavior with type-I band alignment. These heterostructures exhibit remarkable optical absorption in the visible and near-infrared regions, and at room temperature, charge carriers exhibit relatively high mobility for holes in one direction and for electrons in the perpendicular direction.All these six AlN/BP vdWHs have high carrier mobility (of the order of 105cm2V-1s-1), which is comparable to materials with high carrier mobility such as graphene. The energy gap of the AlN and BP monolayers are 4.04 eV and 1.4 eV, respectively, by HSE06 approximation, and for AlN/BP heterostructures are about 1.428 eV to 1.550 eV for all cases. The CBO and VBO of the AlN/BP vdWHs heterostructures are 2.21157 eV and 0.2057 eV, respectively.