Picosecond Photoluminescence Decay Time in Colloidal Nanocrystals: The Role of Intrinsic and Surface States

Morello, Giovanni; Anni, Marco; Cozzoli, Pantaleo Davide; Liberato, Manna; Cingolani, Roberto; De Giorgi, Milena

doi:10.1021/jp072783h

Picosecond time-resolved photoluminescence measurements were performed on CdSe core and CdSe/ZnS core/shell colloidal quantum dots (QDs). Photoluminescence (PL) emission is observed to originate from intrinsic (1U and (1L bright states with lifetimes of 60 and 450 ps, respectively, and from a long living component with nanosecond lifetimes. The latter is attribuited to the emission from surface states (ss) approximately 16 and 13 meV below the (1L state for core and core/shell QDs, respectively. We show that in the temperature range between 15 and 70 K the three recombination processes compete and they are thermally populated through different pathways.

Titolo:	Picosecond Photoluminescence Decay Time in Colloidal Nanocrystals: The Role of Intrinsic and Surface States
Autori:	MORELLO, GIOVANNI [Membro del Collaboration Group] (Corresponding) ANNI, Marco [Membro del Collaboration Group] COZZOLI, Pantaleo Davide [Membro del Collaboration Group] Liberato MANNA [Membro del Collaboration Group] CINGOLANI, Roberto [Membro del Collaboration Group] DE GIORGI, Milena [Membro del Collaboration Group] mostra contributor esterni nascondi contributor esterni
Data di pubblicazione:	2007
Rivista:	JOURNAL OF PHYSICAL CHEMISTRY. C
Abstract:	Picosecond time-resolved photoluminescence measurements were performed on CdSe core and CdSe/ZnS core/shell colloidal quantum dots (QDs). Photoluminescence (PL) emission is observed to originate from intrinsic (1U and (1L bright states with lifetimes of 60 and 450 ps, respectively, and from a long living component with nanosecond lifetimes. The latter is attribuited to the emission from surface states (ss) approximately 16 and 13 meV below the (1L state for core and core/shell QDs, respectively. We show that in the temperature range between 15 and 70 K the three recombination processes compete and they are thermally populated through different pathways.
Handle:	http://hdl.handle.net/11587/109229
Appare nelle tipologie:	Articolo pubblicato su Rivista

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http://hdl.handle.net/11587/109229

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