Annealing and surface conduction on hydrogen peroxide treated bulk melt grown, single crystal ZnO

Abstract

We report on the studies carried out on hydrogen peroxide treated melt grown, bulk single crystal ZnO samples. Results show the existence of two shallow donors in the as-received ZnO samples with energy levels (37.8 ± 0.3) meV that has been suggested as Zni related and possibly H-complex related and (54.5 ± 0.9) meV which has been assigned to an Al-related donor. Annealing studies performed on the hydrogen peroxide treated samples reveal the existence of a conductive channel in the samples in which new energy levels have been observed, Zn vacancies, related to the Group I elements, XZn. The surface donor volume concentration of the conductive channel was calculated from theory developed by D. C. Look [1]. Results indicate an increase in surface volume concentration with increasing annealing temperature from 6.0´1017 cm-3 at 200°C to 4.37´1018 cm-3 at 800°C.