Effect of AlN Buffer Layers on GaN/MnO Structure

We have investigated the effect of AlN buffer layers on characteristics of GaN films grown on nearly lattice matched MnO (111) substrates by pulsed laser deposition (PLD). We have found that the polarity of the GaN films grown on the MnO substrates changes from the N-polarity to the Ga-polarity with the use of AlN buffer layers. Atomic force microscopy (AFM) observations and photoluminescence (PL) measurements have revealed that the surface morphology and the optical properties of the GaN films on MnO can be improved by the AlN buffer layers.