Near-band-edge slow luminescence in nominally undoped bulk ZnO
Monteiro, T Neves, AJ Carmo, MC Soares, MJ Peres, M Wang, J Alves, E Rita, E Wahl, Ulrich
Amer inst physics
Journal of Applied Physics vol:98 issue:1 pages:-
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. (c) 2005 American Institute of Physics.