Deposition of nanocomposite Cu–TiO₂ using heterogeneous colliding plasmas

Abstract

The formation of CuTiO₂ nanocomposites has been observed in an experiment in which laser plasma plumes of Cu and Ti collide and stagnate in an oxygen atmosphere. The inherent advantage of this technique lies in its simplicity and flexibility where laser, target composition and geometry along with ambient atmosphere are all controllable parameters through which the stoichiometry of the deposited nanocomposites may be selected. The experiment has been performed at three oxygen ambient pressures 10⁻⁴, 10⁻², 10⁰ mbar and we observe its effect on stoichiometry, and morphology of the deposited nanocomposites. Here, we show how the stoichiometry of deposited nanocomposites can be readily controlled by changing just one parameter, namely the ambient oxygen pressure. The different peaks of photoluminescence spectra $\lambda =390{\text{ nm}}\;\left( {E=3.18{\text{ eV}}} \right)$ corresponding to the anatase phase of TiO₂, along with the peaks at λ = 483 nm (E = 2.56 eV) and 582 nm (E = 2.13 eV) of deposited nanocomposites, shows the doping/blending effect on the band gaps which may potentially be of value in solar cell technology. The technique can, in principle, be extended to include nanocomposites of other materials making it potentially more widely applicable.