Radiative Recombination of Spatially Extended Excitons in (ZnSe/CdS)/CdS Heterostructured Nanorods

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• 作者：Nishshanka N. Hewa-Kasakarage ; Maria Kirsanova ; Alexander Nemchinov ; Nickolas Schmall ; Patrick Z. El-Khoury ; Alexander N. Tarnovsky ; Mikhail Zamkov
• 刊名：Journal of the American Chemical Society
• 出版年：2009
• 出版时间：January 28, 2009
• 年：2009
• 卷：131
• 期：3
• 页码：1328-1334
• 全文大小：331K
• 年卷期：v.131,no.3(January 28, 2009)
• ISSN：1520-5126

文摘

We report on organometallic synthesis of luminescent (ZnSe/CdS)/CdS semiconductor heterostructured nanorods (hetero-NRs) that produce an efficient spatial separation of carriers along the main axis of the structure (type II carrier localization). Nanorods were fabricated using a seeded-type approach by nucleating the growth of 20−100 nm CdS extensions at [000 ± 1] facets of wurtzite ZnSe/CdS core/shell nanocrystals. The difference in growth rates of CdS in each of the two directions ensures that the position of ZnSe/CdS seeds in the final structure is offset from the center of hetero-NRs, resulting in a spatially asymmetric distribution of carrier wave functions along the heterostructure. Present work demonstrates a number of unique properties of (ZnSe/CdS)/CdS hetero-NRs, including enhanced magnitude of quantum confined Stark effect and subnanosecond switching of absorption energies that can find practical applications in electroabsorption switches and ultrasensitive charge detectors.