Thick and homogeneous layers of porous TiO2 (anatase and amorphous phases) have been prepared by anodization of Ti foils in fluoride solutions. The porous TiO2 layers have been investigated by electron microscopy, Raman spectroscopy and photovoltage spectroscopy. The nanostructure of the porous TiO2 layers depends sensitively on the pH and on the concentration of the NH4F solution. The photovoltage spectra of as-prepared samples are dominated by defects (electron traps) below the bandgap of anatase. The defects are removed after annealing in air.
ASJC Scopus subject areas
- Condensed Matter Physics