Coating of TiO2 thin films on particles by a plasma chemical vapor deposition process

TiO2 thin films were experimentally coated on glass beads by means of a rotating cylindrical plasma chemical vapor deposition (PCVD) reactor. The morphologies and growth rates of the TiO2 thin films before and after heat treatment were measured for various process conditions. The precursors for the TiO2 films were generated from TTIP by plasma reactions, and they were deposited on the glass beads to become TiO2 thin films. The TiO2 thin films coated on the glass beads became more uniform by heat treatment. The TiO2 thin films grew more quickly on the glass beads with increasing mass flow rate of TTIP, reactor pressure, or rotation speed of the reactor. As the applied electric power decreases, the thickness of the thin films on the glass beads increases. This experimental study shows that the use of a rotating cylindrical PCVD reactor can be a good method to coat high-quality TiO2 thin films uniformly on particles.