EPR and Thermoluminescence in ZnO Single Crystals with Anionic Vacancies
Source: Journal of Applied Spectroscopy, Volume 68, Number 3, 6 May 2001 , pp. 502-507(6)
Abstract:The radiation defects created in hydrothermal ZnO–Li single crystals by irradiating them with electrons, protons, and high-energy ions have been investigated. The anionic vacancies (F-centers) in ZnO are established to be the centers of radiationless recombination of the charge carriers with a photoionization energy of 2.3 eV (a signal of the photo-EPR with the g-factor for the F^+-center: g_∥ = 1.9948 and g_⊥ = 1.9963). The anionic vacancies in the form of the F and F^+ states are a good reference of the electron and hole processes. The [F_Li]^×-centers that correspond to the oxygen vacancies localized near the point defects Li_Zn are detected. In the temperature range 530–660 K, ZnO crystals display thermally stimulated processes such as the healing of anionic vacancies (530–630 K) and the disappearance of the [F_Li]^×-centers (610–660 K).
Document Type: Regular Paper
Publication date: May 6, 2001