Lattice vibrations and optical properties of wurtzite InN in the reststrahlen region

The lattice vibrations and optical properties of wurtzite InN are studied by the first-principle calculations based on the density functional theory. The phonon spectra of lattice vibration are calculated under the Generalized-Gradient Approximation (GGA). The optical properties are investigated based on the phonon spectra. The phonon dispersion curve and the phonon density of state are calculated and compared with the existing experimental data. The calculation indicates that InN has a metal-like behavior. Our calculation shows that the fundamental vibration is therefore infrared active in wurtzite structure semiconductors.

► The phonon dispersion of InN is calculated based on the first-principle using the PWSCF program.
► The components of high-frequency dielectric constant ε∞ and Born effective charge Z⁎, which are perpendicular and parallel to c axis, together with their average values are obtained by the numerical calculation.
► The optical properties of InN are investigated based on the phonon dispersion.
► The anti-crossing behavior of A1(TA) and E2(low) is proved.