First-principles study of structural, elastic, electronic and lattice dynamic properties of AsxPyN1-x-yB quaternary alloys

Information on the energy band gaps, the lattice parameters and the lattice matching to available substrates is a prerequisite for many practical applications. A pseudopotential plane-wave method as implemented in the ABINIT code is used to the AsxPyN1-x-yB quaternary alloys lattice matched to BP substrate to predict their energy band gaps and lattice dynamic properties. The range of compositions for which the alloy is lattice matched to BP is determined. Very good agreement is obtained between the calculated values and the available experimental data. The compositional dependence of direct and indirect band gaps has been investigated. We study the variation of elastic constants, the optical phonon frequencies (omega(TO) and (omega(LO)), the high-frequency dielectric coefficient epsilon(infinity) and the born effective charge Z(center dot) with P concentration. (C) 2009 Elsevier B.V. All rights reserved.