A Novel BN Polymorph in P4/mbm Phase with a (4,4) Nanotube

Herein, based on density functional theory, a new boron nitride structure derived from diamond is designed, and its stability is also proved. The new boron nitride structure is denoted as P4/mbm BN. The elastic moduli (bulk modulus, shear modulus, and Young's modulus) of P4/mbm BN are slightly greater than those of C-72 and T carbon, and the shear modulus and Young's modulus are larger than those of P-4m2 B7N7, B11N11, and B15N15. The shear modulus and Young's modulus of P4/mbm BN exhibit a smaller mechanical anisotropy than that of P-4m2 B7N7, B11N11, and B15N15, where P-4m2 B15N15 exhibits the greatest mechanical anisotropy of shear modulus and Young's modulus. The anisotropy of shear modulus in the (100), (010) plane of P-4m2 B15N15 is 26.5 times that of P4/mbm BN, and the mechanical anisotropy of Young's modulus in (110) plane of P-4m2 B15N15 is 35.6 times that of P4/mbm BN. P4/mbm BN is a wide and indirect bandgap semiconductor material with bandgap of 4.8 eV. Compared with silicon carbide and gallium nitride, P4/mbm BN has a wider bandgap, it might be more suitable for making high temperature, high frequency, radiation resistance, and high-power devices.