Comparison of quantum confinement effects on the electronic absorption spectra of direct and indirect gap semiconductor nanocrystals

Journal Article · Sun Dec 11 23:00:00 EST 1994 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.73.3266· OSTI ID:6660897

Tolbert, S H; Herhold, A B; Johnson, C S; Alivisatos, A P ^[1]

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1. Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States)

The size dependent electronic absorption spectra of CdSe nanocrystals have been measured in a diamond anvil cell. Under pressure, these nanocrystals are reversibly converted from a direct gap wurtzite structure to a rock salt structure which has an indirect gap in the bulk. It is thus possible to compare the influence of quantum confinement on direct and indirect transitions in nanocrystals of the same size. The ratio of oscillator strength between direct and indirect structures does not change with size, indicating that zero-phonon transitions are not occurring in the indirect nanocrystals.

• OSTI ID: 6660897
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 73:24; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ABSORPTION SPECTRA
CADMIUM COMPOUNDS
CADMIUM SELENIDES
CHALCOGENIDES
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRONIC STRUCTURE
ENERGY GAP
OSCILLATOR STRENGTHS
PHASE TRANSFORMATIONS
PRESSURE DEPENDENCE
SELENIDES
SELENIUM COMPOUNDS
SPECTRA