Phase selective growth and properties of rhombohedral and cubic indium oxide

Abstract

Phase selective growth of rhombohedral and cubic indium oxide polytypes was studied. The selective growth of different polytypes was achieved by adjusting substrate temperature and trimethylindium flow rate during metal organic chemical vapor deposition on c-plane sapphire. The optical band gaps of the cubic and rhombohedral phases were determined to be ∼3.7 and ∼3.0eV, respectively. On the basis of the performed structural investigations, a phenomenological model of the nucleation and growth of highly textured cubic In2O3 on Al2O3 (0001) is proposed.

Ab‐initio theory of semiconductor band structures: New developments and progress

“…The resulting QP energy gaps are 3.10 eV (bcc) and 3.26 eV (rh). These values are somewhat in contrast to the direct gaps of 3.7 eV (bcc) and 3.0 eV (rh) derived recently from optical-absorption spectra [73]. The explanation for the discrepancy in the bcc case is the fact that the lowest optical transitions …”

“…According to the above discussions, the HSE03 starting point for the QP approach should give an excellent framework to answer the open questions. There are two stable or metastable polymorphs, a body-centered cubic (bcc) bixbyite structure SG206 and a rhombohedral (rh) high-pressure rh-phase SG167 [72,73]. Since the bixbyite structure has 40 atoms in the primitive unit cell but the high-pressure phase only 10 atoms, the numerical effort allows a full HSE03 + 0 0 G W calculation only for the rh polymorph.…”

The thermoelectric properties of In2O3 thin films deposited by direct current magnetron sputtering

“…Based on the relation between α , photon energy hυ and the optical band gap E g and Tauc plot, the optical band gap E g of all the samples are found to be 3.75 eV. These values are roughly in accordance with the onset of strong optical absorption of single crystalline bcc In 2 O 3 [29] but smaller than those prepared by spray pyrolysis [11]. Figure 3 shows the dependence of the conductivity on the temperature.…”

Phase stability, electronic structure, and optical properties of indium oxide polytypes

“…The first experimental data for In 2 O 3 -III is already available. 11 The absorption coefficient was measured for the energy range 0-6 eV, which contain the E 0 peak. Calculated absorption spectra was shifted to 1.35 eV toward higher energies to fit the E 0 peak to experimentally determined location.…”

“…Nanoparticles of In 2 O 3 in rhombohedral structure have been synthesized by hydrothermal method, followed by post annealing at moderate temperatures and pressures. 10 Phase selective growth of this phase was also demonstrated 11 by means of metal organic chemical vapor deposition (MOCVD) method at high substrate temperatures (> 550 o C) and low (>4 (µmol/min)) trimethylindium flow rates. Furthermore, it is found 12 that this phase can be formed upon annealing in air at >550 o C of the amorphous indium zinc oxide.…”