Plasmon Dynamics in Colloidal Au2Cd Alloy鈥揅dSe Core/Shell Nanocrystals

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• 作者：Pablo Guardia ; Kseniya Korobchevskaya ; Alberto Casu ; Alessandro Genovese ; Liberato Manna ; Alberto Comin
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：February 26, 2013
• 年：2013
• 卷：7
• 期：2
• 页码：1045-1053
• 全文大小：561K
• 年卷期：v.7,no.2(February 26, 2013)
• ISSN：1936-086X

文摘

Metal鈥搒emiconductor nanocrystal heterostructures are model systems for understanding the interplay between the localized surface plasmon resonances in the metal domain and the relaxation of the excited carriers in the semiconductor domain. Here we report the synthesis of colloidal Au₂Cd (core)/CdSe (shell) nanocrystal heterostructures, which were characterized extensively with several structural and optical techniques, including time-resolved fluorescence and broad-band transient absorption spectroscopy (both below and above the CdSe band gap). The dynamics of the transient plasmon peak was dominated by the relaxation of hot carriers in the metal core, its spectral shape was independent of the pump wavelength, and the bleaching lifetime was about half a picosecond, comparable with the value found in the AuCd seeds used for the synthesis.

Keywords:

colloidal nanocrystal heterostructures; plasmonic materials; plasmon bleaching dynamics; charge transfer; fluorescence quenching; metal鈭抯emiconductor nanojunctions