High-pressure structural and electronic properties of InN

Abstract

We theoretically study the electronic properties and pressureinduced solid-solid phase transformation of InN by using the first-principles pseudopotential method. The wurtzite (B4), rocksalt (B1), zinc-blende (B3), CsCl-type (B2), and Cmcm crystal structures of InN have been considered. The calculations indicate that the phase transitions from B4 phase to B1 phase and B3 structure to B1 structure occur at a transition pressure of 10.2 and 9.6 GPa, respectively. The detailed volume changes during the phase transformations were analyzed. Moreover, the analysis of the band structure indicates that the bandgap of B4 phase is direct, while B1 phase is indirect under high-pressure. The mechanism of these changes of band structures was analyzed. The positive pressure derivative of the indirect and direct gap indicates that it is impossible to make B1 phase of InN metallic up to 200 GPa.

Epitaxial Growth of Cubic and Hexagonal InN Thin Films via Plasma-Assisted Atomic Layer Epitaxy

“…Since there are no bcc unit cells with 4 atoms in the lattice and InN stoichiometry, a bcc phase is highly unlikely. The measured value of the lattice parameter is similar to the reported theoretical value of 4.64 Å for the high pressure phase rocksalt structure InN lattice . Experimentally such structure was not reported before.…”

“…The measured value of the lattice parameter is similar to the reported theoretical value of 4.64 Å for the high pressure phase rocksalt structure InN lattice . 22 Experimentally such structure was not reported before. Additional measurements of Laue diffraction (LD) patterns on this sample in both transmission as well as grazing incidence reflection mode, revealed only a spotty diffraction pattern even after a 24 hr exposure, indicating that this sample has an epitaxial nature and not a powder/polycrystalline nature.…”

“…With the use of a relation, the lattice constant, a = 4.64[(1 − 11.66/B) −1 ] 1/3 and bulk modulus, B, of 192 GPa 22 for the rocksalt structure, the estimated d spacings in the [110] and [100] directions are 4.74 and 6.70 Å, respectively. The value of the lattice parameter along the [100] direction is consistent with the lattice parameter obtained from the XRD measurement.…”

Structural, electronic and vibrational properties of InN under high pressure

“…Bulk modulus B 0 and its pressure derivative B 0 ' extracted from EOS fitting are listed in Table 1 . The structural parameters derived in this work agree well with the reported calculated and experimental values [25–29] . However, the pressure derivative B ' of the B4 (wurtzite) phase is different from the experimental value reported in Ref.…”