Multi-structural TiO2 film synthesised by an atmospheric pressure plasma-enhanced chemical vapour deposition microwave torch

In this study, a microwave plasma torch working at atmospheric pressure has been used for TiO2 thin film synthesis. We first optimised the deposition conditions in order to avoid the formation of powder in the plasma phase. Then, the characterisation of the TiO2 films deposited in the optimised conditions revealed that both morphology and phase structure of the film are radial dependent. At the centre, the film is crystallised, exhibiting a well-defined columnar microstructure. Meanwhile, at the periphery, the film is amorphous, with a cauliflower-like structure. •TiO2 crystallised films were grown at atmospheric pressure and low temperature.•The homogeneous phase reactions in the plasma are reduced by changing parameters.•Both structural and morphological changes in the films are discussed.