Preparation and Characterization of Bi2Ti2O7 Thin Films from Self-Assembled Monolayer Technique

Bi2Ti2O7 thin films were prepared on the functionalized octadecyl-trichloro-silane (OTS)-covered fluorine-doped SnO2 (FTO) substrates by self-assembled monolayer (SAM) technique using Bi(NO3)(3)center dot 5H(2)O and Ti (OC4H9)(4) as raw materials. The test of the hydrophilicity of the substrate surface indicates that UV irradiation turns the surface of OTS-SAM film from hydrophobicity to hydrophilicity and realizes the functionalization. The composition, microstructure and microtopography of Bi2Ti2O7 thin films were characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray Spectrometry (EDS), Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM). The results indicate that the as-prepared Bi2Ti2O7 thin films are homogeneous and dense when the concentration of the deposited solution is 0.02 mol.L-1. The dielectric constant is 153 at 100 kHz and the dielectric loss is 0.089 for a 0.4 mu m-thick film annealed at 560 degrees C for 1 h.