MN-DOPED NANOMETER-SIZE ZNS CLUSTERS IN CHITOSAN FILM MATRIX PREPAREDBY ION-COORDINATION REACTION

A novel method, the so called ion-coordination reaction, was introduce d to prepare nanometer-sized Mn-doped ZnS clusters stuck to a chitosan medium. A possible growth mechanism of the Mn-doped ZnS clusters in a chitosan film has been proposed. The X-ray diffraction showed that th e ZnS clusters have a cubic structure like bulk crystals and the clust er sizes were estimated from the diffraction linewidth to be 2-4 nm ba sed on Scherre's equation. The emission of Mn ion was observed through band-to-band excitation of ZnS. The excitation spectrum showed a larg e blue shift relative to that of ZnS bulk material. The effect of Zn i on concentration on the luminescence intensity reveals that the emissi on efficiency of Mn ion increases with the decrease of the ZnS cluster size. (C) 1998 Elsevier Science B.V. All rights reserved.