Spontaneous spectral diffusion in CdSe quantum dots

Mark J. Fernée (1) , Taras Plakhotnik (2) , Yann Louyer (3) , Bradley N. Littleton (4) , Christian Potzner (5) , Philippe Tamarat (1) , Paul Mulvaney (5) , Brahim Lounis (1)

1 lp2n-01,lp2n-12
2 School of Mathematics and Physics [Brisbane]
3 LOMA - Laboratoire Ondes et Matière d'Aquitaine
4 King‘s College London
5 School of Chemistry [Melbourne]

Spectral diffusion of the emission line of single colloidal nanocrystals is generally regarded as a purely random process. Here we show that each new spectral position has a finite memory of previous spectral positions, as evidenced by persistent anti-correlations in time series of spectral jumps. The anti-correlation indicates there is a finite probability of the charge distribution around the nanocrystal returning to a previous configuration. We show both statistically and directly that this memory manifests as an observable spontaneous "relaxation" in the absence of a pump laser.

Mots clés: CdSe nanocrystals; spectral diffusion

Domaines: Autre [cond-mat.other]

Mark J. Fernée, Taras Plakhotnik, Yann Louyer, Bradley N. Littleton, Christian Potzner, et al.. Spontaneous spectral diffusion in CdSe quantum dots. Journal of Physical Chemistry Letters, 2012, 3 (12), pp.1716-1720. ⟨10.1021/jz300456h⟩. ⟨hal-00717579⟩