Luminescence upconversion in colloidal double quantum dots

Zvicka Deutsch, Lior Neeman, Dan Oron

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

Luminescence upconversion nanocrystals capable of converting two low-energy photons into a single photon at a higher energy are sought-after for a variety of applications, including bioimaging and photovoltaic light harvesting. Currently available systems, based on rare-earth-doped dielectrics, are limited in both tunability and absorption cross-section. Here we present colloidal double quantum dots as an alternative nanocrystalline upconversion system, combining the stability of an inorganic crystalline structure with the spectral tunability afforded by quantum confinement. By tailoring its composition and morphology, we form a semiconducting nanostructure in which excited electrons are delocalized over the entire structure, but a double potential well is formed for holes. Upconversion occurs by excitation of an electron in the lower energy transition, followed by intraband absorption of the hole, allowing it to cross the barrier to a higher energy state. An overall conversion efficiency of 0.1% per double excitation event is achieved.

Original languageEnglish
Pages (from-to)649-653
Number of pages5
JournalNature Nanotechnology
Volume8
Issue number9
DOIs
Publication statusPublished - Sep 2013

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Quantum Dots
Luminescence
Photons
Semiconductor quantum dots
quantum dots
Electrons
luminescence
Quantum confinement
Nanostructures
Electron transitions
Nanoparticles
Nanocrystals
Electron energy levels
Rare earths
Conversion efficiency
Crystalline materials
Light
energy
photons
Chemical analysis

ASJC Scopus subject areas

  • Bioengineering
  • Biomedical Engineering
  • Materials Science(all)
  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics
  • Medicine(all)

Cite this

Luminescence upconversion in colloidal double quantum dots. / Deutsch, Zvicka; Neeman, Lior; Oron, Dan.

In: Nature Nanotechnology, Vol. 8, No. 9, 09.2013, p. 649-653.

Research output: Contribution to journalArticle

Deutsch, Zvicka ; Neeman, Lior ; Oron, Dan. / Luminescence upconversion in colloidal double quantum dots. In: Nature Nanotechnology. 2013 ; Vol. 8, No. 9. pp. 649-653.
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