Near-band-edge slow luminescence in nominally undoped bulk ZnO

• Author(s): Monteiro, T. ; Neves, A.J. ; Carmo, M.C. ; Soares, M.J. ; Peres, M. ; Wang, J. ; Alves, E. ; Rita, E. ; Wahl, U.
• Date: 2005
• Persistent ID: http://hdl.handle.net/10773/6148
• Origin: RIA - Repositório Institucional da Universidade de Aveiro
• Subject(s): Zinc compounds; II-VI semiconductors; Wide band gap semiconductors; Photoluminescence; Time resolved spectra; Excitons; Impurity states
• Document Type: Article
• Language: English

Description

We report the observation of slow emission bands overlapped with the near-band-edge steady-state luminescence of nominally undoped ZnO crystals. At low temperatures the time-resolved spectra are dominated by the emission of several high-energy bound exciton lines and the two-electron satellite spectral region. Furthermore, two donor-acceptor pair transitions at 3.22 and 3.238 eV are clearly identified in temperature-dependent time-resolved spectroscopy. These donor-acceptor pairs involve a common shallow donor at 67 meV and deep acceptor levels at 250 and 232 meV. FCT/FEDER - POCTI/CTM/45236/02