First-principles study of structural, elastic, electronic and lattice dynamic properties of AsxPyN1−x−yAl 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−yAl quaternary alloys lattice matched to AlP substrate to predict their energy band gaps and optical properties. The range of compositions for which the alloy is lattice-matched to AlP is determined. Very good agreement is obtained between the calculated values and the available experimental data. The Debye temperature increase when the bulk modulus is enhanced. We study the variation of elastic constants, the optical phonon frequencies (ωTO and ωLO), the static and high-frequency dielectric coefficient ɛ(0) and ɛ(∞) and the dynamic effective charge Z* with P concentration (y).

Research highlights▶ The range of compositions for which the alloy is lattice matched to AlP is determined. ▶ We study the variation of elastic constants, the optical phonon frequencies (ωTO and ωLO), the high-frequency dielectric coefficient ɛ(∞) and the dynamic effective charge Z* with P concentration.