摘要： β-Gallium oxide (β-Ga2O3) is attractive as a novel material for (opto)electronics, especially high-power electronics and solar-blind photodetectors (PDs). It has an ultrawide direct bandgap of around 4.8–4.9 eV at room temperature and high thermal and chemical stabilities [1, 2]. The theoretical electrical breakdown field (Ebr) of β-Ga2O3 is known to be (cid:1)8 MV/cm, and 3.8 MV/cm of Ebr has been experimentally demonstrated in a recent report, recording a higher value than those of GaN and SiC. Baliga’s figure of merit (BFOM) of β-Ga2O3 is also superior among some of the other popular wide-bandgap semiconductors, such as 4H-SiC and GaN [3–6]. These outstanding properties have led to a large number of reports on various electrical devices based on β-Ga2O3 including metal-oxide-semiconductor field-effect transistors (MOSFETs), metal-semiconductor field-effect transistors (MESFETs), and Schottky barrier diodes [7–10]. Furthermore, the wide bandgap of β-Ga2O3 provides intrinsic solar blindness that allows fabrication of solar-blind PDs without the need for additional optical filters that block light in the range of long wavelength [11]. Single-crystal β-Ga2O3 is commercially available as a various of growth methods exist; especially the edge-defined film-fed growth (EFG) method that can be used to grow bulk β-Ga2O3 substrates with high crystal quality [12, 13]. However, the low thermal conductivity of β-Ga2O3 has to be considered when fabricating high-power electrical devices.