Dislocations generated by indentation and subsequent annealing at elevated temperatures up to 800C in high quality (00•1) wafers of ZnO single crystals were investigated by transmission X-ray topography and photoluminescence. Damages induced by indentation in ZnO wafers were guessed to lead to dislocated regions from X-ray topographic images. Photoluminescence intensities of 3.36eV near-band edge peak and 2.4eV deep emission band in ZnO decreased drastically, with increasing in annealing temperature up to 800C, irrespective of dislocated or non-dislocated regions. The development of a new emission band at 2.8 to 3.0eV was found in non-damaged ZnO after annealing at 700 and 800C, which suggested that dislocations suppressed the development of the new peak.

Dislocations of ZnO Single Crystals Examined by X-ray Topography and Photoluminescence. Yoshino, K., Yoneta, M., Yonenaga, I.: Journal of Materials Science: Materials in Electronics, 2008, 19[2], 199-201