Hydrogen impurities and shallow donors in SnO2studied by infrared spectroscopy

Autor: Gunter Lüpke, Erik Spahr, Figen Bekisli, W. Beall Fowler, Lynn A. Boatner, Michael Stavola
Rok vydání: 2011
Předmět:
Zdroj: Physical Review B. 84
ISSN: 1550-235X
1098-0121
DOI: 10.1103/physrevb.84.035213
Popis: Hydrogen has been found to be an important source of $n$-type conductivity in the transparent conducting oxide SnO${}_{2}$. We have studied the properties of H in SnO${}_{2}$ single crystals with infrared spectroscopy. When H or D is introduced into SnO${}_{2}$ by annealing in an H${}_{2}$ or D${}_{2}$ ambient at elevated temperature, several O-H and O-D vibrational lines are produced, along with the low-frequency absorption characteristic of free carriers. To probe the relationship between H and the free carriers it introduces, the thermal stability of free carrier absorption and its relationship to the thermal stabilities of O-H lines have been examined. Two H-related donors are found: one is stable at room temperature on a time scale of weeks, and a second is stable up to 600 ${}^{\ensuremath{\circ}}$C. These electrically active defects are found to interact with other O-H centers and can be converted from one to another by thermal treatments. The vibrational modes have been found to have distinctive polarization properties that provide an important test of microscopic defect models for the several O-H and (O-H)${}_{2}$ centers we have observed.
Databáze: OpenAIRE