Structural and optical properties of heteroepitaxial beta Ga2O3 films grown on MgO (100) substrates

• Published in: Thin solid films Vol. 520; no. 13; pp. 4270 - 4274
• Main Authors: Kong, Lingyi, Ma, Jin, Luan, Caina, Mi, Wei, Lv, Yu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.04.2012; Elsevier
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Domain structure; Exact sciences and technology; Gallium oxide; Materials science; Metal-organic vapor phase epitaxy; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films; Vapor phase epitaxy; growth from vapor phase; Thin films; Metal-organic vapor phase epitaxy; Domain structure; Optical properties; Gallium oxide; Photonic band gap; Epitaxial layers; Magnesium oxide; Visible spectra; VPE; Crystallinity; Transmittance; Transmission electron microscopy; MOVPE method; Growth mechanism; Heteroepitaxy; Microstructure
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2012.02.027

Gallium oxide (Ga2O3) films were deposited on MgO (100) substrates by metalorganic vapor phase epitaxy. Structure analyses showed that the films deposited at 550–700°C were epitaxial β-Ga2O3 films with an out of plane relationship of β-Ga2O3(100)||MgO(100). The film deposited at 650°C showed the best crystallinity and the microstructure of the film was investigated by high resolution transmission electron microscopy. A theoretical model of the growth mechanism was proposed and the in-plane epitaxial relationship was given to be β-Ga2O3[001]||MgO . A four-domain structure inside the epitaxial film was clarified. The β-Ga2O3 film deposited at 650°C showed an absolute average transmittance of 95.9% in the ultraviolet and visible range, which had an optical band gap of 4.87eV. ► Beta Ga2O3 epitaxial films were deposited on MgO(100) substrate. ► A theoretical model of the growth mechanism was proposed. ► The transmittance of the film in the ultraviolet and visible region exceeded 95.9%.