Abstract

We have investigated the optical properties ofcolloidal seed-grown CdSe (seed)/CdTe (arms) nanotetrapodsboth experimentally and computationally. The tetrapods exhibita type-II transition arising from electrons localized in the CdSeseed region and holes delocalized in the CdTe arms, along witha residual type-I recombination in long-arm tetrapods.Experimentsand theory helped to identify the origin of both types oftransitions and their size dependence. In particular, timeresolvedexperiments performed at 10 K evidenced a sizedependent,long living type-II radiative emission arising fromthe peculiar electron-hole wave function localization. Temperature-dependent photoluminescence (PL) studies indicate that, at high temperature (>150 K), the main process limiting the PLquantum efficiency of the type-I PL is thermal escape of the charge carriers through efficient exciton-optical phonon coupling. Thetype-II PL instead is limited both by thermal escape and by the promotion of electrons from the conduction band of the seed regionto that of the arms, occurring at T > 200 K.

Autore Pugliese

• Creti' Arianna , Della Sala Fabio , Lomascolo Mauro , De Giorgi Milena

Tutti gli autori

• G. Morello; A. Fiore; R. Mastria; A. Falqui; A. Genovese; A. Cretì;M. Lomascolo; I.R. Franchini; L. Manna; F. Della Sala; R. Cingolani; M. De Giorgi

Titolo volume/Rivista

Journal of physical chemistry. C

Anno di pubblicazione

2011

ISSN

1932-7447

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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