Simulation of electronic density of states and optical properties of PbB4O7 by first-principles DFT method

Abstract

First-principles calculations based on the density functional theory and the generalized gradient approximation were carried out to systematically investigate the electronic structure and linear optical properties of lead tetraborale (PbB4O7; PTB) single crystals. An indirect band gap of 4.34 eV is obtained. The valence band top is at the X-point and the conduction band is at the Γ-point. The calculated total and partial densities of states indicate that the lop valence band is constructed from O 2p states and the low conduction hand mainly consists of Pb 6p states. The optical absorption spectra show several prominent structures but with very small directional anisotropy. PTB crystals have a higher refractive index but a small birefringence. The calculated frequency-dependent refractive index is in good agreement with experimental data. © 2009 WILEY-VCH Verlag GmbH & Co. KQaA.