Donor-related defect states in ZnO substrate material

State-of-the-art commercial ZnO substrate materials grown either by chemical vapor transport or by a hydrothermal technique are investigated by photoluminescence. We identify all the sharp lines around 3.36 eV as donor bound exciton (D-0, X) lines, based on their associated two-electron satellites (TES). Study of the TES transitions yields information on the donor specific 1s <----> 2p single-particle binding energy of each donor, which allows us to determine the donor binding energies and the correlation to the exciton binding energies, i.e. Haynes' rule. (C) 2003 Elsevier B.V. All rights reserved.