Luminescence of ZnO nanopowders

The luminescence of ZnO nanocrystals prepared by different methods was studied under pulsed electron beam excitation. It is shown that the luminescence intensity depends on the nanocrystal sintering conditions and does not depend on the nanocrystal size within the range 10-50 nm. The relative luminescence intensities for the 3.32 eV (free exciton) and similar to3.20 eV (bound exciton) bands showed a dependence on nanocrystal size. The role of the nanocrystal surface in excitonic luminescence is discussed. (C) 2004 Elsevier Ltd. All rights reserved.