Substrate polarity and surface pretreatment temperature dependence of ZnO homoepitaxy

- ZnO homoepitaxy on ZnO substrates with different polarities has been investigated.
- The pretreatment of ZnO substrates would influence the properties of the grown film.
- The chemical activity of Zn- and O-polar surfaces is very different.
- ZnO film grown on an appropriate pretreated substrate has good morphological and crystallographic quality.
- Unintentional carbon impurities could be suppressed on ZnO film grown on pretreated Zn-polar substrate.
- ZnO film grown pretreated Zn-polar substrate is beneficial to the formation of acceptors.