Structural and Optical Characterization of Nitrogen-doped TiO2 Thin Films Deposited by Spray Pyrolysis on Fluorine Doped Tin Oxide (FTO) Coated Glass Slides
Date
2012Author
Ayieko, C. O.
Musembi, R. J.
Waita, S. M.
Aduda, Bernard O
Jain, P. K.
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Undoped and nitrogen-doped titanium dioxide (TiO2) thin films of 400 nm thick deposited by spray pyrolysis
were structurally and optically characterized. The effect of substrate temperature on the optical properties of the films was
also investigated. Structural studies of the films were undertaken by X-ray diffraction (XRD). Energy dispersive X-ray
(EDX) spectrum analysis was used to confirm the presence of nitrogen atoms in the film after doping. The optical
properties such as refractive index (n), energy band gap (Eg) and Urbach energy (Eu) were determined from
spectrophotometric measurements of reflectance and transmittance for both undoped and doped films. The Undoped films
had an energy band gap of 3.25 eV while the doped films had band gap of 2.90 eV. The Urbach energy increased from 1.00
eV for undoped films to 1.04 eV for the nitrogen-doped films. The reduction in energy band gap and increase in Urbach
energy was attributed to the introduction of nitrogen impurity tail states on either the conduction band or the valence band
of the titanium dioxide.
Citation
International Journal of Energy Engineering 2012,Publisher
School of Physical Sciences