Abstract
Electron mass anisotropy in the Nb-doped anatase (TNO) was determined by polarized infrared spectroscopy measurements for (012)-oriented TNO epitaxial films. The electron mass along the axis, , derived by Drude analyses, was found to be , which was 3–6 times larger than that along the axis, , . This large anisotropy was attributed to not only the anisotropic crystal structure but also the -orbital-dominated conduction band. These results indicate that control of crystallographic orientation is of crucial importance for realizing high conductivity in polycrystalline TNO films.
- Received 31 July 2008
DOI:https://doi.org/10.1103/PhysRevB.79.165108
©2009 American Physical Society