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Updated: Apr 25, 2026
Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Mercury telluride colloidal quantum dots: electronic structure, size-dependent spectra, and photocurrent detection up
Sean E Keuleyan1, Philippe Guyot-Sionnest, Christophe Delerue
1James Franck Institute, University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States .
Abstract:
HgTe colloidal quantum dots are synthesized with high monodispersivity with sizes up to ∼15 nm corresponding to a room temperature absorption edge at ∼5 μm. The shape is tetrahedral for larger sizes and up to five peaks are seen in the absorption spectra with a clear size dependence. The size range of the HgTe quantum dots is extended to ∼20 nm using regrowth. The corresponding room temperature photoluminescence and absorption edge reach into the long-wave infrared, past 8 μm. Upon cooling to liquid nitrogen temperature, a photoconductive response is obtained in the long-wave infrared region up to 12 μm. Configuration-interaction tight-binding calculations successfully explain the spectra and the size dependence. The five optical features can be assigned to sets of single hole to single electron transitions whose strengths are strongly influenced by the multiband/multiorbital character of the quantum-dot electronic states.
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