Nanocrystalline order of zinc oxide thin films grown on optical fibers

The crystallographic orientation of polycrystalline zinc oxide films grown on optical fibers using single-source chemical vapor deposition (SS CVD) of basic zinc acetate have been studied. The films have been characterized using near-edge x-ray absorption fine structure. For the SS CVD ZnO growth on planar substrates, the film orientation can be varied from randomly oriented to highly c-axis oriented. In contrast, the films grown on optical fibers were either randomly oriented or a,b-axis oriented, depending on growth conditions. The correlations between growth conditions and the crystallographic properties of the films on fibers were discussed. The results suggest that factors such as curvature may have an effect on the crystallinity of film growth.