Fabrication of Ge quantum dots doped TiO2 films with high optical absorption properties via layer-by-layer ion-beam sputtering

Ge quantum dots (QDs)-doped TiO2 films were prepared by ion-beam sputtering. TEM results showed Ge QDs were in a uniform size distribution and high density. XPS indicated that Ge incorporated in the TiO2 films was in elemental form. The Stranski-Krastanov growth mode was accounted for the growth of Ge QDs in TiO2 films by AFM analysis. Optical absorption spectra exhibited the optical response of the Ge QDs-doped TiO2 films was shifted from UV to the near infrared region, suggesting a good optical absorption property. (C) 2011 Elsevier B.V. All rights reserved.