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β-Ga₂O₃ is an ultra-wide bandgap semiconductor that has attracted much attention because of the applications it promises. Hydrogen centers have been found to be a cause of n-type conductivity and also to interact with cation vacancies in several transparent conducting oxides [1]. Ga₂O₃ shows similar behaviors and a family of hydrogenated Ga(1) vacancy centers based on shifted configurations of the vacancy [2-4]. Infrared spectroscopy coupled with theory have revealed a wealth of information about these defects. The combination of O-H vibrational spectra, their isotope dependence, and polarization properties with theoretical analysis has determined the microscopic properties of the hydrogen centers observed in this low-symmetry structure [5-7]. This work is the result of collaborations with W. B. Fowler, S. J. Pearton and the Ph.D students listed in the references below [5-7].
[1] M. D. McCluskey et al., J. Mater. Res. 17, 2190 (2012).
[2] J. B. Varley et al., J. Phys. Condens Matter 23, 334212 (2011).
[3] A. Kyrtsos, et al., Phys. Rev. B 95, 245202 (2017).
[4] W. B. Fowler et al., Appl. Phys. Lett. 117, 142101 (2020).
[5] P.Weiser et al., Appl. Phys. Lett. 112, 232104 (2018).
[6] Ying Qin et al., ECS J. Solid State Sci. Technol. 8, Q3103 (2019).
[7] A. Portoff, A. Venzie, et al., J. Appl. Phys. 127, 055702 (2020).