Magnetic Properties of Nonmagnetic Nanostructures: Dangling Bond Magnetic Polaron in CdSe Nanocrystals

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• 作者：Anna Rodina ; Alexander L. Efros
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：June 10, 2015
• 年：2015
• 卷：15
• 期：6
• 页码：4214-4222
• 全文大小：493K
• ISSN：1530-6992

文摘

We predict theoretically that nonmagnetic CdSe nanocrystals may possess macroscopic magnetic moments due to the formation of dangling-bond magnetic polarons (DBMPs). A DBMP is created in optically pumped nanocrystals by dynamic polarization of dangling bond spins (DBSs) at the nanocrystal surface during radiative recombination of the ground state 鈥渄ark鈥?exciton assisted by a spin-flip of the DBS. The formation of DBMPs suppresses the radiative recombination of the dark exciton and leads to a temperature-dependent contribution to the Stokes shift of the photoluminescence. This model consistently explains the experimentally observed low-temperature photoluminescence features of nonmagnetic CdSe nanocrystals as manifestations of their spin-related magnetic properties.