Characterization of β-Ga2O3 thin films on sapphire (0001) using metal-organic chemical vapor deposition technique

Ga2O3 thin films have been deposited on sapphire (0001) substrates at different substrate temperatures by metal-organic chemical vapor deposition. Trimethylgallium and oxygen were used as precursors for gallium and oxygen, respectively. Structural and optical properties of the films have been investigated. X-ray diffraction and high resolution transmission electron microscopy measurements identified an epitaxial relationship of β-Ga2O3 (2¯01)||Al2O3 (0001) with β-Ga2O3<010>||Al2O3<11¯00> and β-Ga2O3<102>||Al2O3<112¯0>. The average transmittance of the obtained films in the visible wavelength range was over 92.3% and the band gap was about 4.73–4.96 eV.

► β-Ga2O3 films have been prepared on Al2O3 (0001) substrates by MOCVD.
► A schematic diagram is proposed to clarify the growth mechanism.
►  The epitaxial relationship is β-Ga2O3 (2¯01)||Al2O3 (0001) with β-Ga2O3<010>||Al2O3<11¯00>.
► The average transmittance for the Ga2O3 samples in the visible range is over 92.3%.