Formation of hydrophilic and photocatalytically active TiO 2 thin films by plasma based ion implantation and deposition

Titanium dioxide thin films were deposited near room temperature by plasma based ion implantation and deposition with the voltage pulses, accelerating the ions towards the substrate, ranging from 0 kV to 10 kV. Correspondingly, an increase of average energy per deposited particle from 2.5 eV to 450 eV was obtained. Even for the highest energy, a mixture of anatase and rutile is present. The increase in deposited energy was closely correlated with an increased sensitivity towards UV‐A radiation with the surface energy increasing from 25 up to 100 mN/m after illumination at 1 mW/cm 2 , corresponding to a hydrophilic and photocatalytically active phase. Additional influences of the substrate type – Si(100), fused silica and thermal oxide on silicon – were found, despite a layer thickness of about 300 nm. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)