Hokkaido and Kyoto Universities Measure Electron Effective Mass in Alpha-Gallium Oxide at About 40% of a Free Electron, Above the 25% Theoretical Prediction
Researchers at Hokkaido University and Kyoto University in Japan, publishing in ACS Applied Electronic Materials, prepared thin films of alpha-gallium oxide (α-Ga₂O₃) using mist chemical vapour deposition and added varying amounts of germanium to provide conducting electrons. Measuring the films' electron concentration and thermopower, the team estimated the effective mass of electrons at approximately 40% of a free electron's mass, higher than the theoretically predicted value of 25%; the team said this difference could be part of the reason electrons move less easily through alpha-gallium oxide than expected.
The team also measured a thermal conductivity of approximately 19 watts per meter-kelvin, which remained almost unchanged even when the germanium concentration increased, showing that adding germanium can improve electron movement without significantly changing heat transfer. Alpha-gallium oxide can withstand very strong electric fields and is a candidate material for next-generation power electronic devices. The paper, by Hiromichi Ohta and colleagues, has DOI 10.1021/acsaelm.6c01639.
Source: ACS Applied Electronic Materials
Published by GSM · USA (original Chinese edition)
Photo: 图中是研究人员在实验室中进行氧化镓等氧化物半导体材料生长研究。Wikimedia Commons — U.S. Air Force AFRL by Keith C Lewis, Public domain
