Regensburg 2019 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 16: Focus Session: Oxide Semiconductors for Novel Devices III
HL 16.9: Vortrag
Dienstag, 2. April 2019, 11:45–12:00, H34
Temperature dependence of the Seebeck coefficient of epitaxial β-Ga2O3 thin films — •Johannes Boy1, Martin Handwerg1, Robin Ahrling1, Rüdiger Mitdank1, Günter Wagner2, Zbigniew Galazka2, and Saskia F. Fischer1 — 1Novel Materials Group, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany — 2Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin, Germany
In the past years, β-Ga2O3 crystals and thin films have proved to be promising materials for high power devices. However, one drawback is the low thermal conductivity[1,2], which enhances the energy-dissipation by Joule heating. One approach could be a direct cooling using the Peltier effect. For this purpose values of the Seebeck coefficient of β-Ga2O3 need to be known.
In this work, the temperature dependence of the Seebeck coefficient of homoepitaxial metal organic vapor phase grown, silicon doped β-Ga2O3 thin films was measured relative to aluminum. For room temperature we found the relative Seebeck coefficient of Sβ-Ga2O3-Al=(−300±20) µV/K. At high bath temperatures T>240 K, the scattering is determined by electron-phonon-interaction. For lower bath temperatures between T=100 K and T=300 K, an increase in the magnitude of the Seebeck coefficient is explained in the frame of Strattons formula.
[1] M. Handwerg, et al., Semicond. Sci. Technol. 30, 024006 (2015).
[2] M. Handwerg, et al., Semicond. Sci. Technol. 31, 125006 (2016).