Electronic and optical properties of h-BN nanosheet: A first principles calculation

Based on ab-initio calculations, we investigate the electronic and linear optical properties of hexagonal boron nitride (h-BN) nanosheet using the full potential linearized augmented plane wave method in the framework of the density functional theory (DFT). The frequency dependent optical properties like dielectric tensor, absorption coefficient, optical conductivity, refraction and extinction coefficients and energy loss function spectrum of the h-BN nanosheet are calculated for both parallel (E vertical bar vertical bar k) and perpendicular (E vertical bar vertical bar z) electric field polarizations. The dielectric function is derived within the random phase approximation (RPA) for these calculations. The results show that the h-BN nanosheet has a semiconductor character with a wide band gap of about 4.96 eV. The optical conductivity in E vertical bar vertical bar x direction and E vertical bar vertical bar z direction starts with a gap of about 2.92 eV and 6.73 eV, respectively, confirms that this nanosheet has semiconductor properties. The calculated results are in good agreement with available experimental data. These results propose potential application for the development of the BN nano-structures in electronic and optoelectronic devices. (C) 2015 Elsevier B.V. All rights reserved.