ZnO nanorods growth on sapphire substrates using aqueous solution with microwave heating and their photoluminescence properties

ZnO nanorods were grown on a-, c- and r-plane sapphire substrates using aqueous solution with microwave irradiation heating. ZnO nanorods about 200 nm diameter with c-axis orientation were grown independently on the orientation of the substrates. Photoluminescence (PL) spectrum at 6 K showed a dominant peak at 3.3609 eV (I-6) with the width as narrow as 2.2 meV comparable to that of epitaxially grown single-crystalline ZnO films. The PL properties were improved by thermal annealing process without generating structural defects. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim