Semi-insulating β-Ga2O3 single crystals through vanadium doping: Growth, Optical and Terahertz characterization

We report the growth of electrically resistive, high quality vanadium-doped β-Gallium Oxide (β-Ga2O3) single crystals via the optical floating zone growth technique. The characteristic properties of such high resistive V-doped β-Ga2O3 are significantly different compared to the undoped, n-type V-doped and other acceptor-doped crystals. We study the optical absorption in the UV-visible and IR range, temperature-dependent photoluminescence, polarization-dependent Raman spectra and the terahertz transmission properties in the 0.2–2.6 THz range. The V-doped insulating Ga2O3 crystals can be used as an alternative insulating substrate for low leakage devices. Further, the strong anisotropy in terahertz transmission makes it an ideal material for optical applications in the THz region.