Berlin 2018 – scientific programme
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DS: Fachverband Dünne Schichten
DS 13: Oxide Semiconductors for Novel Devices (Focussed Session): Session III
DS 13.1: Invited Talk
Tuesday, March 13, 2018, 09:30–10:00, E 020
Electron transport in beta-gallium oxide — •Rebecca L. Peterson1, Zumrad Kabilova1, and Cagliyan Kurdak2 — 1Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, USA — 2Department of Physics, University of Michigan, Ann Arbor, Michigan, USA
The sesquioxide semiconductor gallium oxide is currently drawing attention for power electronics and deep ultraviolet optoelectronics applications, due to its ultra-wide bandgap. Gallium oxide has several crystal polytypes. The stable beta-phase has a bandgap of approximately 4.8 eV, a monoclinic crystalline structure, and bulk substrates are commercially available. Here, we present our experimental and theoretical work on charge transport in bulk (010) β−Ga2O3, in which the extrinsic tin doping of 1018 cm−3 is close to the Mott metal-insulator transition point. A peak electron mobility of 95 cm2V−1s−1 was measured at 185K. Across a wide temperature range, a two-band conduction model applies, consisting of a impurity band in parallel with the conduction band, as was observed previously for n++ (201) β−Ga2O3 [1]. At low temperature, we find that conduction is via variable-range hoping through the impurity band. At high temperatures, phonon scattering of conduction band electrons dominates, similar to lightly-doped (100) β−Ga2O3 [2]. This work was supported by DARPA/SPAWAR under award N66001-14-1-4046. [1] T. Oishi, K. Harada, Y. Koga, and M. Kasu: Japan. J. Appl. Phys. 55, (2016) 030305; [2] A. Parisini and R. Fornari, Semicond. Sci. Technol. 31, (2016) 035023.