Optical and electrical properties of sol-gel spin coated titanium dioxide thin films

Abstract

In this work; TiO2 thin films were deposited on glass and stainless steel substrates by sol-gel spin coating method. The films deposited on glass were annealed at different temperatures (Ta) in the range of 200 to 500 0C and that are deposited on steel substrate were annealed at 800 0C. The optical properties of TiO2 thin films were studied by using UV-VIS spectroscopy and photoluminescence (PL) spectroscopy. The transmittance on the average was found to ≥ 80 % and is found to sensitive to Ta . The PL spectra exhibited the strong emission band associated with band- to- band transition around 390 nm and the two weak bands at 480 and 510 nm associated to the oxygen defects and surface defects respectively. The currentvoltage (I-V) characteristics of the Al/TiO2 /steel capacitors were studied and analysed with application of various current mechanisms. Analysis reveals that the conduction in Al/TiO2/steel capacitors is governed by Poole-Frenkel mechanism.