Excitonic Resonance in Semiconductor鈥揗etal Nanohybrids

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• 作者：Juan I. Climente ; Jose L. Movilla ; Guido Goldoni ; Josep Planelles
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：August 18, 2011
• 年：2011
• 卷：115
• 期：32
• 页码：15868-15874
• 全文大小：892K
• 年卷期：v.115,no.32(August 18, 2011)
• ISSN：1932-7455

文摘

We use a configuration interaction approach within the envelope function approximation to study the nature of the excitonic resonance in nanohybrids, composite nanoparticles (NPs) combining a semiconducting and a metallic segment in contact. With reference to recent experimental reports, we specifically study CdS-based nanorods with metallic NPs deposited at the tips (matchstick) or metallic coatings (core鈥搒hell). The excitonic states are computed taking into account both the renormalization of the electron鈥揾ole interaction and self-energy effects induced by the metallic segment on the electron鈥揾ole pair, as well as by the dielectric environment, through an induced charge numerical approach. In neutral matchstick structures, the metal NP has only a minor influence (1 meV) on the excitonic states. When the metallic NP is charged, the exciton becomes rapidly red-shifted and spatially indirect. In contrast, in neutral core鈥搒hell structures the exciton energy red-shifts by tens of millielectronvolts.