Electrochromic Nanocrystal Quantum Dots
Congjun Wang,
Moonsub Shim,
Philippe Guyot-Sionnest*
Incorporating nanocrystals into future electronic or optoelectronic
devices will require a means of controlling charge-injection processes
and an understanding of how the injected charges affect the properties
of nanocrystals. We show that the optical properties of colloidal
semiconductor nanocrystal quantum dots can be tuned by an
electrochemical potential. The injection of electrons into the
quantum-confined states of the nanocrystal leads to an electrochromic response, including a strong, size-tunable, midinfrared absorption corresponding to an intraband transition, a bleach of the visible interband exciton transitions, and a quench of the narrow band-edge photoluminescence.
James Franck Institute, University of Chicago, Chicago, IL 60637, USA.
*
To whom correspondence should be addressed.
E-mail:pgs{at}uchicago.edu