Texture and morphology of ZnO grown on nanocrystalline p-sexiphenyl thin films

Growth of ZnO by molecular beam epitaxy on submonolayer p-sexiphenyl (6P) films consisting of differently shaped and terminated nanocrystals is studied. The morphology and crystallographic structure of ZnO are analysed by cross-sectional transmission electron microscopy (TEM). The inorganic-on-organic interface is remarkably abrupt and the 6P nanocrystals remain unimpaired as revealed by TEM and complementary photoluminescence measurements. The wurtzite ZnO overlayer shows a distinct columnar structure with a preferential c-axis alignment. The influence of the ZnO growth direction and 6P crystal termination on the structural properties is discussed.