ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Starting from the large photofragmentation cross sections recently reported for mass-selected alkali–halide cluster and nanocrystal beams [X. Li, R. D. Beck, and R. L. Whetten, Phys. Rev. Lett. 68, 3420 (1992)], we have obtained optical absorption spectra for ionic compound clusters in the ultraviolet charge-transfer bands. The smaller members of the CsI series, 3〈n〈14, show distinct absorption edges in the 4.6–5.8 eV region—just below the bulk exciton band near 5.9 eV—and the smallest cluster with an onset near the bulk is Cs14I13+, which is also a (3,3,3) nanocrystal. To help account for these features, we have computed minimum-energy structures for the entire series using a classical electrostatic potential, and have derived a simple model for the absorption energy, following deBoer. The locations of the spectral features are compared to the predicted energies, and good qualitative agreement is found.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.464831
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