Novel oxides
Bixbyite In2O3
The stable form of indium oxide is cubic (bixbyite) and has 40 atoms in its unit cell. This leads to interesting properties, like 16 infrared active optical phonons, a variety of valence bands, and complications in first-principles calculations due to the extreme computational cost. We investigated singly crystals and epitaxial thin films with different free-electron concentrations to study man-body effects on the band structure, the conduction band nonparabolicity, and effective electron masses.
Furthermore, the dielectric function up to a photon energy of 40eV yielded the possibility to benchmark first-principles calculations and shed light onto the effect of lattice screening.
α-Ga2O3
Corundum-like Ga2O3 is a metastable polytype of gallia. Intriguingly, it has the same crystal structure than sapphire (α-Al2O3), is thus alloyable, and it can be donor doped. We are interested in the fundamental optical properties, its comparison to sapphire, the anisotropy, and the effective electron mass.
