Optical absorption spectra of lead iodide nanoclusters

Optical absorption spectra of nanoclusters of lead iodide, synthesized by the colloidal technique, have been investigated. It is shown that the absorption peaks are due to different orders of interband transitions of a nominally single size of particles rather than the first-order transitions of a number of discrete sizes of particles, as reported earlier. The model used to explain the spectra of lead iodide has also been used to account for the optical absorption peaks of colloidal mercuric iodide and bismuth tri-iodide. [S0163-1829(98)01443-X].