Presentation Information
[10p-PB1-11]Energy Band Structure of Nb-Doped TiO2 Films Examined by UPS and LEIPS
〇Chikai Sato1, Takanori Itoh1, Ryota Kimura2, Kenichi Kaminaga2, Yuji Matsumoto2 (1.NISSAN ARC Ltd., 2.Tohoku Univ.)
Keywords:
Oxide semiconductor,Electron Spectroscopy,Energy band
Nb-doped TiO2 films are known as transparent semiconductors (n-type) with electrical conductivity comparable to that of ITO. First-principles calculations and other studies have reported that the origin of this excellent conductivity is due to the formation of hybridized orbitals involving d-electrons from Ti and Nb at the bottom of the conduction band. However, there are very few experimental data and discussions regarding energy bands, particularly the conduction band. On the other hand, ultraviolet photoelectron spectroscopy (UPS) and low-energy inverse photoelectron spectroscopy (LEIPS), which are electron spectroscopic analysis methods, are techniques that can directly obtain information on the valence band and conduction band in the electronic state, respectively, and are suitable for energy band investigations. Therefore, in this study, we investigated the energy bands by performing UPS/LEIPS analysis on TiO2 films with different Nb doping levels to examine the physical origin of the electrical conductivity of these samples.