Quantum Mazes: Luminescent Labyrinthine Semiconductor Nanocrystals Having a Narrow Emission Spectrum

Journal Article (Journal Article)

We exploit the polytypism of group II-VI semiconductors and the long-range dipolar interactions typical of CdSe nanoparticle formation to modulate the geometrical structure and the optical emission properties of novel branched CdSe nanocrystals through shape-dependent quantum confinement effects. X-ray diffraction confirms that these materials incorporate crystalline domains of cubic zinc-blende and hexagonal wurtzite within a polycrystalline growth form whose geometry can be controlled by varying thermodynamic conditions. In particular, labyrinthine-shaped nanoparticles of tunable dimensions are reproducibly synthesized based on a heterogeneous reaction between cadmium acetate in a solution in hexadecylamine and trioctylphosphine with Se as a solid precursor at a relatively low temperature (110 °C). The resulting highly branched CdSe structures resemble labyrinthine patterns observed in magnetic fluids and superconductors films in magnetic fields, and in lipid films and other materials where strong dipolar interactions "direct" large-scale pattern formation. Surprisingly, these novel maze-like structures emit light within a narrow bandwidth (full-width at half-maximum ≈33- 42 nm) of the visible spectrum (508 nm< λ<563 nm), so the regular dimensions of the core regions of these branched structures govern their emission characteristics rather than overall nanoparticle size. This property should make these materials attractive for applications where luminescent materials having tunable emission characteristics and a narrow emission frequency range are required, along with the insensitivity of the particles' luminescent properties to environmental conditions. © 2007 by the American Chemical Society.

Full Text

Duke Authors

Cited Authors

  • De Paoli Lacerda, SH; Douglas, JF; Hudson, SD; Roy, M; Johnson, JM; Becker, ML; Karim, A

Published Date

  • November 1, 2007

Published In

Volume / Issue

  • 1 / 4

Start / End Page

  • 337 - 347

Electronic International Standard Serial Number (EISSN)

  • 1936-086X

International Standard Serial Number (ISSN)

  • 1936-0851

Digital Object Identifier (DOI)

  • 10.1021/nn700111c

Citation Source

  • Scopus