Photoemission investigation of compound semiconductor monodisperse clusters

Journal Article · Thu Jun 04 00:00:00 EDT 1998 · Journal of Vacuum Science and Technology A

DOI:https://doi.org/10.1116/1.577328· OSTI ID:1542300

Tobin, J. G. ^[1]; Colvin, V. L. ^[2]; Alivisatos, A. P. ^[2]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2. Univ. of California, Berkeley, CA (United States)

We have used synchrotron radiation photoemission to probe the valence and core level electronic structure of compound–semiconductor monodisperse clusters (nanocrystals). These clusters emitted a 10% or less variation relative to the mean diameter and were attached to the metal substrates via alkane chains. Direct evidence of gap broadening due to size variation in CdS clusters was observed. The novel utilization of alkane chain attachment is the key to eliminating the otherwise debilitating problem of sample charging, as occurs with powders. The quality of sample preparation was confirmed by other methods such as transmission electron microscopy, Raman scattering, and x–ray diffraction. Our report provides a direct link between photoemission studies of expitaxial ultrathin films of compound semiconductors, the photon–spectroscopy measurements of cluster powders and the existing theories of quantum confinement in reduced dimensionality structures.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF)
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1542300
• Journal Information: Journal of Vacuum Science and Technology A, Journal Name: Journal of Vacuum Science and Technology A Journal Issue: 3 Vol. 9; ISSN 0734-2101
• Publisher: American Vacuum Society / AIP
• Country of Publication: United States
• Language: English