Utilizing Spectroscopy and Optical Microscopy to Characterize Titanium Dioxide Thin Films

Abstract

This paper presents the surface electronic structure and morphological characteristics of the nano-crystalline titanium dioxide (nc TiO2) films derived from the two different sol-gels. Using Scanning tunneling microscopy/spectroscopy (STM/S), it was found that the particles of nc-TiO2 produced from batch A have a surface band gap of ~3.3 eV while the particles of nc-TiO2 produced from batch B have a surface band gap of ~2.6 eV. On other hand, the small particles have aggregated together to form larger particles ranging from ~120 nm to 150 nm in size and distributed randomly over the surface of the batch A nc-TiO2 films. For batch B nc-TiO2films, the small particles have formed larger particles but with their size ranging from 200 nm to 225 nm. That is ascribed to differences between sol-gels used to prepare nc-TiO2 films. As a result of that, the electric power of batch A nc-TiO2/P3HT solar cells is enhanced by more than 8 times in comparison with batch B solar cells.