Dopant−Carrier Magnetic Exchange Coupling in Colloidal Inverted Core/Shell Semiconductor Nanocrystals

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• 作者：Vladimir A. Vlaskin ; Rmi Beaulac ; Daniel R. Gamelin
• 刊名：Nano Letters
• 出版年：2009
• 出版时间：December 9, 2009
• 年：2009
• 卷：9
• 期：12
• 页码：4376-4382
• 全文大小：271K
• 年卷期：v.9,no.12(December 9, 2009)
• ISSN：1530-6992

文摘

Dopant−carrier magnetic exchange interactions in semiconductor nanostructures give rise to unusually large Zeeman splittings of the semiconductor band levels, raising possibilities for spin-based electronics or photonics applications. Here we evaluate the recently highlighted possibility of confinement-induced kinetic s−d exchange coupling in doped ZnSe/CdSe inverted core/shell nanocrystals. Magneto-optical studies of a broad series of Co²⁺- and Mn²⁺-doped core, inverted core/shell, and isocrystalline core/shell nanocrystals reveal that the dominant spectroscopic effects caused by CdSe shell growth around doped ZnSe core nanocrystals arise from hole spatial relaxation, being essentially independent of the electron−dopant interaction or the heterointerface itself. The general criteria for observation of kinetic s−d exchange coupling in doped nanocrystals are discussed in light of these results.