Polarity control of GaN grown on ZnO (000 1-) surfaces

Abstract

We have investigated the growth temperature dependence of the structural properties of GaN deposited on O-polarity ZnO (000 1-) using pulsed laser deposition. We have found that atomically abrupt GaNZnO heterointerfaces are obtained at growth temperatures reduced to below 500 °C. We have also found that GaN grown at room temperature (RT) exhibits a Ga polarity while that grown at 700 °C exhibits a N polarity. However, it is possible to grow Ga-polarity GaN at 700 °C by the introduction of a RT buffer layer. First principles calculations well explain how Ga-polarity GaN may be grown on atomically flat O-polarity ZnO surfaces at low temperatures. © 2006 American Institute of Physics.