Semiconductor Physics, Quantum Electronics & Optoelectronics. 2014. V. 17, N 1. P. 067-074.
Electron structure of TiO 2 composite films with noble metal nanoparticles
1Taras Shevchenko Kyiv National University,
64, Volodymyrska str., 01601 Kyiv, Ukraine;
Abstract. Thin nanocrystalline films of ТіО2 , TiO2/ZrO2 , TiO2/ZrO2/SiO2 , TiO2/ZrO2/SiO2/Ag and TiO2/ZrO2/SiO2/Au were prepared using the sol-gel synthesis method. In this paper, we determined the bandgap for direct and indirect band-to-band transitions. Optical conductivity of the films was determined using the spectral ellipsometry method. Depending on the nanocomposite composition, optical conductivity is of different character due to light absorption caused by the presence of the structure intrinsic defects: oxygen vacancies (F2+ , F, and F+ centers), Ti3+ ions and interstitial Ti atoms. Rearrangement of the electron spectrum in these thin films due to the aforementioned defects can improve photocatalytic activity in the UV and visible spectral ranges.
Keywords: anatase, nanocrystalline TiO2 thin films, spectral ellipsometry, optical conductivity.
Manuscript received 07.12.12; revised version received 31.01.14; accepted for publication 20.03.14; published online 31.03.14.