Nanocrystalline TiO2 thin film prepared by low-temperature plasma-enhanced chemical vapor deposition for photocatalytic applications

A PECVD (Plasma-enhanced Chemical Vapor Deposition) process operating at 150 °C has been implemented to prepare micro-columnar porous TiO2 anatase thin films, performing post-annealing at 300 °C for 5 h. Optimized PECVD conditions have enabled us to obtain homogeneous films with thickness equal to 1-2 μm ± 0.2 μm. An anatase seeding interface deposited prior to the PECVD process has enabled us to reduce crystallization time down to 1.5 h. The size of nano-crystals in prepared anatase thin films has been estimated to be 20 nm by applying the Scherrer equation. Besides, the band-gap energy (Eg) of synthesized anatase thin films on quartz was found to be 3.30 eV.