Configuration dependence of the electronic structure and optical properties of BC2N alloys

Abstract

Using the first-principles band structure and total energy method, we have studied the general trend of physical properties of the BC2N alloy as a function of atomic configurations. We found that the mechanical properties of the BC2N alloy are basically determined by the bond components: structures with more C-C and B-N bonds have low energy, high density, and high bulk and shear moduli, which validates the so called the bond counting rule. We also show that the electronic and optical properties of the BC2N alloy are more sensitive to the atomic configuration, thus could be used in future experimental measurement to identify the atomic configuration of BC2N samples. A strong internal electric field produced by the polar interfaces is observed in the long period BC2Nn×n (111) superlattices, which explains the significant band gap decrease as the period n increases. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.