High quality crystal growth and anisotropic physical characterization of β-Ga2O3 single crystals grown by EFG method

Abstract

β-Ga2O3 is an ultra wide-bandgap semiconductor with promising applications in high voltage and temperature electronic devices and deep-ultraviolet optoelectronic devices, and has attracted lots of attention recently. However, there are still many unknowns about the basic properties needed to be explored urgently, which are very important and necessary for the devices design and application. In this work, bulk β-Ga2O3 single crystals with a width of 1 inch were grown by using an optimized edge-defined film-fed growth (EFG) method under Ar plus 50% CO2 atmosphere. High crystalline quality of the as grown crystal has been demonstrated by the high-resolution X-ray diffraction with 43.2 arcsec of the full width at half maximum (FWHM). The fundamental physical properties of different orientated samples, including thermal properties as a function of temperature up to 500 °C, electrical properties, refractive index and hardness were investigated systematically. Moreover, the measurement showed that aluminum turned out to be a good Ohimc electrode for n-type β-Ga2O3 single crystal.