Enhanced field emission properties from well-aligned ZnO nanocones

Well-aligned ZnO nanocones were self-assembled on amorphous carbon using manganese oxide assisted thermal chemical vapor transport and condensation, without any metal catalysts. Compared with the ZnO nanowires fabricated without the manganese oxide assistance, the field emission performance of the ZnO nanocones was greatly improved, lower turn-on electronic fields and higher current densities were achieved with these emitters. Experimental analyses showed that the ZnO nanocones grow vertically and epitaxially on the [0002] oriented ZnO intermediate layer between nanocones and substrate The manganese oxide seems to play a crucial role in the formation of this ZnO intermediate layer.