We fabricated InGaN LEDs prepared on β-Ga<sub>2</sub>O<sub>3</sub> (201) single-crystal substrates. The substrates were produced by
using the edge-defined film-fed growth (EFG) method. A Si-doped GaN epitaxial layer was grown on an electrically
conductive β-Ga<sub>2</sub>O<sub>3</sub> (201) substrate by metal organic chemical vapor deposition (MOCVD). The full-width at half
maximum (FWHM) of (0002) and (101 1) X-ray rocking curves (XRCs) of the Si-doped GaN layer were 220 arcsec and
223 arcsec, respectively. The dark spot density measured by cathode luminescence (CL) was approximately 1.5×10<sup>8</sup> cm<sup>-2</sup>.
The crystalline quality was equal to that of GaN layer on sapphire. We fabricated a vertical LED in the p-side down
configuration. The peak wavelength was approximately 450 nm. The p-contact metal area was 300 ×300 μm<sup>2</sup>. The light
output power did not saturate at 1000 A/cm<sup>2</sup>. This device characteristic indicates the great potential of Ga<sub>2</sub>O<sub>3</sub> for use in