Fabrication and properties of TiO2 nanofilms on different substrates by a novel and universal method of Ti-ion implantation and subsequent annealing

We report a new, novel and universal method to fabricate high-quality titanium dioxide (TiO2) nanofilms on different substrates by a solid phase growth process of ion implantation and subsequent annealing in oxygen atmosphere. Ti ions were implanted into fused silica, soda lime glass, Z-cut quartz, or (0001) alpha-sapphire by a metal vapor vacuum arc (MEVVA) ion source implanter to fluences of 0.75, 1.5 and 3 x 10(17) ions cm(-2) with a nominal accelerating voltage of 20 kV. To understand the influence of the annealing temperature, time, and substrate on the formation and phase transformation of the TiO2 nanofilms, the Ti-ion-implanted substrates were annealed in oxygen atmosphere from 500 to 1000 degrees C for 1-6 h. The formation of TiO2 nanofilms resulted from the slow out-diffusion of implanted Ti ions from the substrates which were then oxidized at the surfaces. The thickness and phase of the nanofilms can be tailored by controlling the implantation and annealing parameters. Since the TiO2 nanofilms are formed under high temperature and low growth rate, they show good crystallinity and antibacterial properties, with good film adhesion and stability, suggesting that the TiO2 nanofilms formed by this method have great potential in applications such as antibacterial and self-cleaning transparent glass.