Effects of growth temperature and oxygen pressure on the properties of heteroepitaxial ZnO thin films on sapphire (0001) substrates by pulsed laser deposition

초록

We report a systematic study on the effect of growth temperature and O-2 pressure on the structural, optical, and electrical properties of heteroepitaxial ZnO thin films prepared by pulsed laser deposition on sapphire (0001) substrates. The combination of high growth temperature and low O-2 pressure was found to improve the crystalline quality of initial heteroepitaxial ZnO films, which can be attributed to the enhanced surface migration of adatoms and thermal energy. The low-temperature photoluminescence spectra from ZnO films were dominated by donor-bound exciton emission with very weak deep level emission. The temperature dependent Hall measurement showed that the films are highly degenerated, mainly due to the high defect density near the interface region. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

키워드