Deposition and composition-control of Mn-doped ZnO thin films by combinatorial pulsed laser deposition using two delayed plasma plumes

Thin films of ZnO doped with manganese were deposited by double-beam, combinatorial pulsed laser deposition. The laser-induced plasmas were studied by means of fast photography and using a Langmuir probe, whereas the films were analyzed by x-ray-diffraction and energy-dispersive x-ray spectroscopy. The effect of the relative delay between plasma plumes on the characteristics of the films was analyzed. It was found that using this parameter, it is possible to control the dopant content keeping the oriented wurtzite structure of the films. The minimum content of Mn was found for plume delays between 0 and 10 μs as the interaction between plasmas scatters the dopant species away from the substrate, thus reducing the incorporation of Mn into the films. Results suggest that for delays shorter than ∼100 μs, the expansion of the second plume through the region behind the first plume affects the composition of the film.