Tuning the optical and electronic properties of colloidal nanocrystals by lattice strain

Andrew M. Smith, Aaron M Mohs, Shuming Nie

Research output: Contribution to journalArticle

504 Citations (Scopus)

Abstract

Strain can have a large influence on the properties of materials at the nanoscale. The effect of lattice strain on semiconductor devices has been widely studied, but its influence on colloidal semiconductor nanocrystals is still poorly understood. Here we show that the epitaxial deposition of a compressive shell (ZnS, ZnSe, ZnTe, CdS or CdSe) onto a soft nanocrystalline core (CdTe) to form a lattice-mismatched quantum dot can dramatically change the conduction and valence band energies of both the core and the shell. In particular, standard type-I quantum-dot behaviour is replaced by type-II behaviour, which is characterized by spatial separation of electrons and holes, extended excited-state lifetimes and giant spectral shifts. Moreover, the strain induced by the lattice mismatch can be used to tune the light emission-which displays narrow linewidths and high quantum yields-across the visible and near-infrared part of the spectrum (500-1,050 nm). Lattice-mismatched core-shell quantum dots are expected to have applications in solar energy conversion, multicolour biomedical imaging and super-resolution optical microscopy.

Original languageEnglish (US)
Pages (from-to)56-63
Number of pages8
JournalNature Nanotechnology
Volume4
Issue number1
DOIs
StatePublished - Jan 1 2009

Fingerprint

Crystal lattices
Electronic properties
Nanocrystals
Semiconductor quantum dots
nanocrystals
Optical properties
Tuning
tuning
optical properties
quantum dots
electronics
Lattice mismatch
Light emission
Quantum yield
Semiconductor devices
Valence bands
Conduction bands
Energy conversion
Excited states
solar energy conversion

ASJC Scopus subject areas

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

Cite this

Tuning the optical and electronic properties of colloidal nanocrystals by lattice strain. / Smith, Andrew M.; Mohs, Aaron M; Nie, Shuming.

In: Nature Nanotechnology, Vol. 4, No. 1, 01.01.2009, p. 56-63.

Research output: Contribution to journalArticle

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