Spontaneously ordered TiO2 nanostructures

Titanium dioxide thin films were deposited on quartz substrates kept at different O2 pressures using pulsed laser deposition technique. The effects of reactive atmosphere and annealing temperature on the structural, morphological, electrical and optical properties of the films are discussed. Growth of films with morphology consisting of spontaneously ordered nanostructures is reported. The films growth under an oxygen partial pressure of 3 × 10−4 Pa consist in nanoislands with voids in between them whereas the film growth under an oxygen partial pressure of 1 × 10−4 Pa, after having being subjected to annealing at 500 °C, consists in nanosized elongated grains uniformly distributed all over the surface. The growth of nanocrystallites with the increase in annealing temperature is explained on the basis of the critical nuclei-size model.