Quantum core- shell

Core/shell-type nanoparticles ovm ated with higher band inorganic materials exhibit high PL quantum yield compared with uncoated dots d K to elimination of surface non-radiative recombination defects. Such core/shell structures as CdSe/CdS [6] and CdSe ZnS [7] have been prepared from organometaHic precursors. 

Kim S, Fisher B, Eisler HJ, Bawendi M (2003) Type-11 Quantum Dots CdTe/CdSe (core/sheU) and CdSe/ZnTe(core/shell) heterostructures. J Am Chem Soc 125 11466-11467 Aharoni A, Mokaii T, Popov 1, Banin U (2006) Synthesis of InAs/CdSe/ZnSe core/ shelll/shell2 structures with bright and stable near-infrared fluorescence. J Am Chem Soc 128 257-264... 

Dabbousi, B. O., Rodriguez-Viejo, J., Mikulec, F. V, Heine, J. R., Mattoussi, H., Ober, R., Jensen, K. F. and Bawendi, M. G. (1997) (CdSe)ZnS core-shell quantum dots synthesis and characterization of a size series of highly luminescent nanocrystallites. J. Phys. Chem. B, 101, 9463-9475. 

Hering, V. R., Gibson, G., Schumacher, R. I., Faljoni-Alario, A. and Politi, M. J. (2007). Energy transfer between CdSe/ZnS core/shell quantum dots and fluorescent proteins. Bioconjug. Chem. 18, 1705-8. 

Huang, B., and Tomalia, D.A. (2005) Dendronization of gold and CdSe/cdS (core-shell) quantum dots with tomalia type, thiol core, functionalized poly(amidoamine) (PAMAM) dendrons. J. Lumin. Ill, 215-223. 

A modified SILAR system has been used to grow CdSe in CdS/CdSe core shell semiconductor nanocrystals.12 A cadmium precursor solution, with CdO dissolved with oleic acid in octadecane, was injected onto the substrate, and the Se solution (Se powder dissolved with tributylphosphine in octadecane) was similarly injected. The temperature of the reaction solution was 185 °C. A CdS outer layer in the CdS/CdSe/CdS colloidal quantum wells was deposited by alternating injections of cadmium and sulfur both in octadecane solutions at 230-240 °C. These structures showed high PL quantum yields (20-40%), relatively narrow emission bands, and tunable emission colors from about 520 to 650 nm depending on the number of CdSe monolayers. 

Fleischhaker, E Zentel, R. 2005. Photonic crystals from core-shell colloids with incorporated highly fluorescent quantum dots. Chem. Mater. 17 1346-1351. 

Fig. 17.10 Schafer et al.14 have observed single mode lasing from core shell CdSe/ZnS nano crystal quantum dots in a glycerine water mixture. The fluorescence spectrum (black line) showed clear peaks of WGM and single mode lasing (grey line) was observed for sufficiently small droplets ( 10 pm) and high pump laser intensities (53 mJ crrT2 in 10 ns pulses at 532 nm). Insert shows the droplet trapped between the electrodes. Reprinted from Ref. 14 with permission. 2008 American Chemical Society...

McBride J, Treadway J, Feldman LC, Pennycook SJ, Rosenthal SJ (2006) Structural basis for near unity quantum yield core/shell nanostructures. Nano Lett 6 1496-1501... 

Lifshitz E et al (2006) Stable PbSe/PbS and PbSe/PbSexSl-x core-shell nanocrystal quantum dots and their applications. J Phys Chem B 110 25356-25365... 

Robelek R, Stefani FD, Knoll W (2006) Oligonucleotide hybridization monitored by surface plasmon enhanced fluorescence spectroscopy with bio-conjugated core/shell quantum dots. Influence of luminescence blinking. Phys Status Solidi A-Appl Mater Sci 203 3468-3475... 

Wang S, Jarrett BR, Kauzlarich SM, Louie AY (2007) Core/Shell quantum dots with high relaxivity and photoluminescence for multimodality imaging. J Am Chem Soc 129 3848-3856... 

Fig. 7 Schematic representation of CdS Mn/ZnS core shell quantum dot surface fimction-alized with silane compounds...

Micic 01, Smith BB, Nozik AJ (2000) Core-shell quantum dots of lattice-matched ZnCdSe2 shells on InP cores Experiment and theory. J Phys Chem B 104 12149-12156... 

When innermost core shells must be treated explicitly, the four-component versions of the GREGP operator can be used, in principle, together with the all-electron relativistic Hamiltonians. The GRECP can describe here some quantum electrodynamics effects (self-energy, vacuum polarization etc.) thus avoiding their direct treatment. One more remark is that the... 

TE0S/H20, NH, Cd (NO ,)2. (NH4)2S CdS core, shell, homogeneously dispersed, or surface bonded quantum dots prepared, depending on sequencing of CdS precipitation and TEOS hydrolysis presence of hexanol strengthened microemulsion against destabilization by ethanol reaction product (35-37)... 

In Dr. M. Gratzel s plenary lecture at IPS-2000,103 he presented the following research topics to improve DSC. 1) Mastering the interfaces, electron transfer dynamics, control of dark current. 2) Charge transport in nanocrystalline films. 3) Panchromatic sensitizers, dye cocktail, quantum dot charge injection. 4) Light management, mixed metal oxide films, core-shell metal oxide films. 5) New... 

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