Spin-on-based fabrication of titania nanowires using a sol-gel process

A spin-on process was employed in the fabrication of titania nanowires. When a groove patterned azobenzene functionalized polymer (AFP) was used as a template, titania nanowires could be fabricated along the grooves via gel cracking, especially when the concentration of sol precursor was low. However, when the sol precursor was deposited on the flat AFP substrate in the form of a thin film (thickness, 80 nm), the gelation of the viscous sol led to the formation of titania nanowires across the large crack opening of the film. A subsequent calcination increased the exposure of the wires and eliminated residual precursors.