Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Spin-flip limited exciton dephasing in CdSe/ZnS colloidal quantum dots

Masia, Francesco ORCID:, Accanto, Nicolo, Langbein, Wolfgang Werner ORCID: and Borri, Paola ORCID: 2012. Spin-flip limited exciton dephasing in CdSe/ZnS colloidal quantum dots. Physical Review Letters 108 (8) , 087401. 10.1103/PhysRevLett.108.087401

[thumbnail of OA-10.pdf]
Download (201kB) | Preview


The dephasing time of the lowest bright exciton in CdSe/ZnS wurtzite quantum dots is measured from 5 to 170 K and compared with density dynamics within the exciton fine structure using a sensitive three-beam four-wave-mixing technique unaffected by spectral diffusion. Pure dephasing via acoustic phonons dominates the initial dynamics, followed by an exponential zero-phonon line dephasing of 109 ps at 5 K, much faster than the ∼10  ns exciton radiative lifetime. The zero-phonon line dephasing is explained by phonon-assisted spin flip from the lowest bright state to dark-exciton states. This is confirmed by the temperature dependence of the exciton lifetime and by direct measurements of the bright-dark–exciton relaxation. Our results give an unambiguous evidence of the physical origin of the exciton dephasing in these nanocrystals.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Biosciences
Physics and Astronomy
Subjects: Q Science > Q Science (General)
Q Science > QC Physics
Publisher: American Physical Society
ISSN: 0031-9007
Funders: EPSRC
Last Modified: 07 Nov 2022 09:07

Citation Data

Cited 47 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics