The Pt/β-Ga2O3 Schottky barrier diode and its temperature-dependent current-voltage characteristics were investigated for power device application. The edge-defined film-fed growth (EFG) technique was utilized to grow the (100)-oriented β-Ga2O3 single crystal substrate that shows good crystal quality characterized by X-ray diffraction and high resolution transmission electron microscope. Ohmic and Schottky electrodes were fabricated by depositing Ti and Pt metals on the two surfaces, respectively. Through the current-voltage (I-V) measurement under different temperature and the thermionic emission modeling, the fabricated Pt/β-Ga2O3 Schottky diode was found to show good performances at room temperature, including rectification ratio of 1010, ideality factor (n) of 1.1, Schottky barrier height (ΦB) of 1.39 eV, threshold voltage (Vbi) of 1.07 V, ON-resistance (RON) of 12.5 mΩ·cm2, forward current density at 2 V (J@2V) of 56 A/cm2, and saturation current density (J0) of 2 × 10−16 A/cm2. The effective donor concentration Nd − Na was calculated to be about 2.3 × 1014 cm3. Good temperature dependent performance was also found in the device. The Schottky barrier height was estimated to be about 1.3 eV–1.39 eV at temperatures ranging from room temperature to 150 °C. With increasing temperature, parameters such as RON and J@2V become better, proving that the diode can work well at high temperature. The EFG grown β-Ga2O3 single crystal is a promising material to be used in the power devices.

A high performance solar-blind photodetector based on Cr-doped gallium oxide (Ga2O3) has been fabricated. A 140nm-thick Ga2O3 layer was mechanically exfoliated from bulk crystal. The photodetector was based on a field effect transistor structure, which showed a very high photo-to-dark current ratio larger than 10 6 and excellent current saturation. When the photodetector was tested with a 254 nm ultraviolet light, the ratio of drain current with and without the UV light reached nearly six orders of magnitude. The dark current was as low as 5 pA. Furthermore, the current rise time and decay time were both about 25 ms. High responsivity of 4.79 × 10 5 A/W and external quantum efficiency of 2.34 × 10 6 also have been achieved at the same time. Index Terms-gallium oxide (Ga2O3), filed-effect-transistor (FET), solar-blind photodetector

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A long list of main group and transition metals, even some lanthanides, have been examined based on first principles studies, to search for potential p-type dopants for β-Ga2O3.

High-quality bulk β-Ga2O3 single crystals have been grown by optimized edge-defined film-fed growth (EFG) method.