Morphology controlled ZnO nanotube grown on CVD graphene layers

Abstract

ZnO nanotube was grown on CVD graphene substrate in controlled manner by combination of bottom-up MOCVD growth method and top-down selective growth mask etching. As-grown ZnO nanotubes were characterized using SEM, TEM and PL. In addition, mammalian cells were cultured on the nanotube array to test for biocompatibility. SEM characterization showed that it is possible to control the morphology of ZnO nanotubes by changing the growth parameters. This was done for Zinc Metal-organic source with different purity as well. Position and dimension of nanotubes were controlled by selective etching of growth mask. Even the CVD-graphene substrate was to from hollow nanotubes which was confirmed with SEM and TEM. In addition, nanotube array was mechanically detached from the original supporting substrate using appropriate binding polymer layer. In this way, thin flexible free-standing nanotube embedded layer was formed by simple mechanical lift-off process. Furthermore, it was possible to confirm that the free-standing layer is relatively biocompatible by showing that cells could be cultured on the free-standing layer for extended period of time.