Core-shell nanocrystals CdSe-ZnSe

Reiss, R, Bleuse, J. and Pron, A. (2002) Highly Luminescent CdSe/ZnSe Core/ Shell Nanocrystals of Low Size Dispersion. Nano Lett., 2,781-4. 

This approach was appUed to heterostructured seeded nanorods, both for CdSe-CdS (type I) and for ZnSe-CdS QD/QR core-shell nanocrystals. The former system was studied extensively, using a variety of optical spectroscopy methods the data acquired suggested a charge separation, where the hole is located in the QlSe core [positioned close to one end of the nanorod (NR)j and the electron extends over the CdS shell [84]. This picture is consistent with a small value of the conduction band offset, typically Ac<0.2eV, extracted from the bulk regime. However, a direct measurement of the band offsets and the consequent charge distribution in such nanocrystals is of major interest... 

P. Reiss, J. Bleuse and A. Pron, Highly luminescent CdSe/ZnSe core/shell nanocrystals of low size dispersion. Nano Letters, 2(7), 781-784 (2002). 

The hot-soup method has also been applied to the production of semiconductor core/shell nanostructures, where a semiconductor nanocrystal is coated with a second semiconductor of wider bandgap. Shown in Figure 23 is a scheme for the synthesis of CdSe/CdS core/shell nanocrystals. These nanostructures were synthesized via a high-temperature route in a mixture of TOP and TOPO (223,224) and via a low-temperature route in pyridine (225). Among the semiconductor core/shell nanomaterials produced were CdSe/ZnS, CdSe/CdS, InAs/InP, InAs/CdSe, InAs/ZnSe, and InAs/ZnS (223,225-228). In these structures, the shell type and thickness allow further control of the optical, electronic, and other properties of semiconductor nanocrystals. For example, the shell may be used to passivate the imperfect surface of the core semiconductor, resulting in significantly improved luminescence efficiency. 

S.K. Tripathi, M. Sharma, Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals. Mater. Research Bulletin 48 (2013) 1837-1844. 

Early reports of ternary core-shell-shell (CSS) structures stem from Reiss et al. and Talapin etaZ. [277, 278]. In the latter case, CdSe nanocrystals stabilized with TOP and TO PO were coated with a shell of CdS or ZnSe. The second (i.e., outermost) shell was composed of ZnS in both cases. According to the authors, the main purpose of the... 

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