Donors and H impurities in SnO$_{2}$ studied by IR spectroscopy

Theory predicts that SnO$_{2}$ is an attractive wide band gap candidate for achieving p-type conductivity. Interstitial H and H$_{O}$ are suggested to be shallow donors in SnO$_{2}$ [1-3]. We have studied the properties of H in SnO$_{2}$ single crystals. An O-H line is observed at 3261 cm$^{-1}$ that is polarized perpendicular to the c direction along with weaker features at 3258 and 3272 cm$^{-1}$. When D is introduced into SnO$_{2}$ by annealing in a D$_{2}$ ambient at 700\r{ }C, a variety of new O-H and O-D lines is produced along with the low-frequency absorption that is characteristic of free carriers. To probe the relationship between H and the free carriers it introduces, we have examined the thermal stabilities of the O-H and O-D lines and their relationship to the thermal stability of the free-carrier absorption. \\[4pt] [1] A.K. Singh \textit{et al}., Phys. Rev. Lett. \textbf{101}, 055502 (2008). \\[0pt] [2] J.B. Varley \textit{et al.,} Phys. Rev. B \textbf{79}, 245206 (2009). \\[0pt] [3] W.M. Hlaing Oo \textit{et al.}, Phys. Rev. B \textbf{82}, 193201 (2010).