Abstract We have prepared nearly monodisperse CdSe nanocrystallites with diameters of 1-4 nm from the rapid pyrolysis of organometallic precursors in a hot coordinating solvent. The nanocrystal structures have been characterized by transmission electron microscopy and electron diffraction. From the absorption spectrum, we have observed the prominent peak of 1S-1S excitonic transition, which is obviously blue-shifted from the bulk bandgap and the largest shift is about 1.25 eV. We have used a theoretical model based on the tight binding approximation to analyze the quantum size effect of these nanocrystallites. The results have been compared with those of the effective mass approximation model.
Received: 15 June 1998
Accepted manuscript online:
PACS:
73.22.-f
(Electronic structure of nanoscale materials and related systems)
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