Slow positrons have been used to study ZnO layers grown on a-axis sapphire and irradiated by 2 MeV O+ ions to fluences from 1012 cm-2 to 1017 cm-2. At low fluences Zn vacancies are observed, and their introduction rate is estimated as 2000 cm-1. At the highest fluences of 1016-1017 cm-2 vacancy clusters are formed. The extent of the primary damage and its recovery is discussed.
- Positron Spectroscopy