Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2008; 53(1): 406-411

Published online July 15, 2008

Copyright © The Korean Physical Society.

ZnO Nanorods and Periodically-Polarity-Inverted Structures for Photonic Devices

Sang Hyun Lee, Katsushi Fujii, Tsutomu Minegishi and Takafumi Yao


We control the morphology of ZnO nanorods and the crystal polarity of ZnO layers for applications to photonic devices. ZnO nanorods are grown through an aqueous reaction. The morphology of the ZnO nanorods is changed to porous by annealing followed by wet chemical etching. The photoluminescence emission intensity from porous ZnO nanorods increases several times compared to that from as-grown nanorods. The enhancement of the emission intensity of the porous ZnO nanorods is explained in terms of an increase in the extraction efficiency of emission. Periodically-polarity-inverted (PPI) ZnO structures are grown on patterned MgO buffers fabricated on $c$-Al$_2$O$_3$ substrates by using plasma-assisted molecular beam epitaxy, in which the patterned MgO consists of 8-nm-thick MgO and 1-nm-thick MgO. Zn-polar ZnO grows on the thick MgO buffer while O-polar ZnO on the thin MgO. Second harmonic generation for incident light at 1060 nm under quasi-phase matching conditions is observed at 503 nm from the PPI structure, thus indicating the feasibility of using PPI ZnO structures for nonlinear optical devices.

Keywords: ZnO, Nanostructure, Crystal polarity, Photonic devices