Optical absorption by nanoparticles of
Department of Physics, University of Calcutta - Calcutta, 700 009,
2 Indian Association for the Cultivation of Science - Calcutta, 700 032, India
Accepted: 22 September 2000
Cuprous oxide ( particles coated with polyacrylamide having diameters in the range from 4.8 to 8.6 nm were prepared by a chemical method. The optical absorption of these particles was found to be characterized by excitons with corresponding energies varying from 2.6 to 2.25 eV in the particle size range mentioned above. A second optical-absorption maximum signifying surface states within the band gap is exhibited by the specimens with relevant energies varying from 2.6 to 1.77 eV in this particle size range.
PACS: 78.66.Jg – Amorphous semiconductors; glasses; nanocrystalline materials / 61.46.+w – Clusters, nanoparticles, and nanocrystalline materials / 81.05.Ys – Nanophase materials
© EDP Sciences, 2000