Nano Lett., 5 (9), 1809 -1813, 2005. 10.1021/nl0511667 S1530-6984(05)01166-5
Web Release Date: August 26, 2005

Copyright © 2005 American Chemical Society

Femtosecond Spectroscopy of Carrier Relaxation Dynamics in Type II CdSe/CdTe Tetrapod Heteronanostructures

P. Peng, D. J. Milliron, S. M. Hughes, Justin C. Johnson, A. Paul Alivisatos, and Richard J. Saykally*

Department of Chemistry, University of California, Berkeley, California 94720-1460

Received June 20, 2005

Revised August 15, 2005

Abstract:

Branched nanocrystal heterostructures synthesized from CdSe and CdTe exhibit a type II band structure alignment that induces separation of charge upon photoexcitation and localizes carriers to different regions of the tetrahedral geometry. The dynamics of carrier relaxation examined with femtosecond pump-probe spectroscopy showed heterostructures having rise times and biexponential decays longer than those of nanorods with similar dimensions. This is attributed to weaker interactions with surface states and nonradiative relaxation channels afforded by the type II alignment.

Download the full text: PDF | HTML