H and D centers in In$_{2}$O$_{3}$ studied by IR spectroscopy

Hydrogen has been predicted to be an important source of n-type conductivity in transparent conducting oxides (TCO's) [1]. We have used IR spectroscopy to investigate the properties of H (and D) in single crystals of the prototypical TCO, In$_{2}$O$_{3,}$ and to test the predictions of recent theory [2]. H (or D) introduces several O-H (or O-D) stretching lines and also the broad absorption arising from free carriers. We have used the vibrational properties of H- (and D-) containing centers as a probe of microscopic structure and as a strategy to monitor H-related reactions that occur upon annealing. [1] M. McCluskey \textit{et al.}, J. Mater. Res. \textbf{27}, 2190 (2012) [2] S. Limpijumnong \textit{et al.}, Phys. Rev. B \textbf{80}, 193202 (2009).