2026-11-09 北海道大学,京都大学
ミストCVD法により作製された高品質α型酸化ガリウム薄膜の熱電能と熱伝導率。熱電能のキャリア濃度依存性から、電子有効質量が0.40 m0であることが分かった。また、熱伝導率は19 W/mKであることが分かった。
＜関連情報＞
- https://www.hokudai.ac.jp/news/2026/11/post-2495.html
- https://pubs.acs.org/aaembp/article-abstract/doi/10.1021/acsaelm.6c01639/5465253/Experimental-Determination-of-Carrier-Effective
ミストCVD法により作製したGeドープα-Ga₂O₃エピタキシャル膜のキャリア有効質量および面直熱伝導率の実験的決定 Experimental Determination of Carrier Effective Mass and Cross-plane Thermal Conductivity in Mist-CVD-Grown Ge-Doped α-Ga2O3 Epitaxial Films
Hiromichi Ohta; Takeru Wakamatsu; Mitsuki Yoshimura; Katsuhisa Tanaka
ACS Applied Electronic Materials Published:November 05, 2026
DOI:https://doi.org/10.1021/acsaelm.6c01639
Abstract
Gallium oxide with the corundum crystal structure (α-Ga2O3) has attracted considerable attention as an ultrawide-bandgap (Eg ∼ 5.3 eV) n-type oxide semiconductor. Theoretical calculations predicted a high electron mobility of approximately 220 cm2 V–1 s–1 with a carrier effective mass (m*) of 0.25 m0 and a relatively low thermal conductivity (κ) of ∼12 W m–1 K–1. However, experimental verification of these properties remains limited. In this study, we systematically investigate the m* and cross-plane κ of Ge-doped α-Ga2O3 epitaxial films grown by mist chemical vapor deposition. X-ray diffraction revealed no significant structural differences among the films. Assuming a parabolic conduction band minimum, m* was estimated from thermopower and carrier-concentration measurements. The obtained m* was approximately 0.4 m0. The cross-plane κ was approximately 19 W m–1 K–1 and showed little dependence on Ge concentration. These results provide a foundation for the development of high-performance α-Ga2O3-based power electronic devices.
