Hydrogen trapped at perturbed Ga(1) vacancies in β-Ga₂O₃

It was discovered several years ago that the primary O-H vibrational absorption in β-Ga₂O₃ arises from two H trapped at a shifted Ga(1) vacancy[1], and that other features arise from one or more H trapped at the same defect with a different shifted configuration[2]. Subsequent work has yielded methods to obtain the dipole directions of such defects[3,4] and is revealing additional versions of defects with these two shifted configurations, but perturbed by lattice defects or atomic impurities, as reported in this meeting[5,6]. We are using the hybrid DFT CRYSTAL17 code[7] to assess candidates for these perturbed configurations and the constraints on these configurations established by the experimental results.

[1] P. Weiser et al., Appl. Phys. Lett. 112, 232104 (2018).
[2] Y. Qin et al., ECS J. Solid State Sci. Technol. 8, Q3103 (2019).
[3] A. Portoff et al., J. Appl. Phys. 127, 055702 (2020).
[4] A. Portoff et al., unpublished.
[5] A. Portoff et al., this meeting.
[6] A. Venzie et al., this meeting.
[7] R. Dovesi et al., WIREs Comput. Mol. Sci., e1360 (2018).