Study on N and O ions irradiation damage in ZnO

Abstract

A clear understanding of irradiation damage behavior in ZnO is crucial for its potential application in space and nuclear radiative environments. Herein, the influences of 90 keV O+ and N+ irradiation damage on ZnO bulk crystals are systematically investigated, in combination with morphological, structural and optoelectronic characterizations. Special attention was paid to reveal the ZnO damage discrepancy induced by different ion irradiations. Results found that while O+ irradiation lead to a slight decrease of electron concentration from 5.54 × 1012 to 2.66 × 1012 cm−3, N+ irradiation resulted in a three orders increase in electron concentration from 5.54 × 1012 to 7.94 × 1015 cm−3. Interestingly, while Zni and its related defect complex Zni-Oi are created by N+ irradiation, abundant VZn related acceptors are emerged and labeled in O+ irradiated ZnO. To the best of our knowledge, this is the first observation of 450 nm VZn emission created by O+ irradiation. Although O+ and N+ have the same irradiation energy and dose as well as a similar radius and mass, the radiation damage caused by O+ is apparent weaker than that of N+. We attribute this phenomenon to the efficient annihilation and recombination of the irradiation defects with the incident oxygen ions during irradiation.