Paper PS-ThP21
Controllable Deposition of TiO₂ Films by Atmospheric Pressure Dielectric Barrier Discharge: Gas Composition Effect and Mechanism

Thursday, November 10, 2016, 6:00 pm, Room Hall D

In this work, various controlled morphologies of TiO₂ films are synthesized by atmospheric pressure argon/oxygen dielectric barrier discharge (DBD) using titanium tetraisopropoxide (TTIP) as precursor. The gas compositions for the formation of TiO₂ films are optimized by adjusting the flow rate of plasmagen gas from 0 to 9.5 L/min, while keeping the flow rate of TTIP and O₂ as constant. The morphology of the deposited films is observed by Scanning Electron Microscopy (SEM). It is found that the morphologies change from columnar film to dense film as the flow rate of plasmagen gas increases. The chemical structures and properties of the deposited films are characterized by means of Infrared Reflection-Absorption Spectroscopy (IRRAS), Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The results show that the films are amorphous with similar chemical compositions. The plasma properties are investigated using Optical Emission Spectroscopy (OES) and Mass Spectrometry (MS). The intensity of Ar* species increase as the flow rate of plasmagen gas increases, which indicates that the concentration of Ar* species have a strong effect on the morphology of the TiO₂ films. The MS measurements show that H⁺, O⁺, H₂O⁺, CO₂⁺, C₃H₆O⁺ and a weak signal of TiO₂⁺ are produced in the plasma. The mechanisms of the TiO₂ films formation from TTIP by DBD are discussed.