Quantum dots composites

R. F. Haglund Jr., Quantum-dot composites for nonlinear optical applications, in R. E. Hummel, P. Wissmann (eds.) Handbook of Optical Properties II Optics of Small Particles, Interfaces, and Surfaces, Vol. 2, CRC Press, New York, 1997, 191. 

Rodriguez-Viejo, J., et al. (1997) Cathodoluminescence and photoluminescence of highly luminescent CdSe/ZnS quantum dot composites. Appl. Phys. Lett. 70, 2132-3134. 

Farmer SC, Patten TE (2001) Photoluminescent polymer/quantum dot composite nanoparticles. Chem Mater 13 3920-3926... 

A major application is the synthesis of high molecular weight water-soluble polymers (e.g., polymers and copolymers of acrylamide, acrylic acid, and its salts) for flocculants and tertiary oil recovery. Other uses are the synthesis of polyaniline/CdSe quantum dots composites [49], hybrid polyaniline/carbon nanotube nanocomposites [50], polyani-line-montmorillonite nanocomposites [51], or in reversible addition-fragmentation chain-transfer-controlled radical polymerization (RAFT) [52]. 

Bratkovsky, A., Ponizovskaya, E., Wang, S.-Y., Holm-strSm, P., Thylen, L., Fu, Y., Agren, H. (2008). A metal-wire/quantum-dot composite metamaterial with negative e and compensated optical loss. Applied Physics Letters, 93,193106(3). 

Hikmet, R.A.M., Talapin, D.V. and Weller, H. (2003) Study of conduction mechanism and electroluminescence in CdSe/ZnS quantum dot composites. Journal of Applied Physics, 93, 3509-14. 

Talroze RV, Shandr3njk GA, Matukhina EV, Vasiliev RB, Merekalov AS, Gaskov AM (2007) Liquid crystal polymers as directing medium creation of organized quantum dots composites. Polym Preprints 48(2) 775-776... 

Jie, G., L. Li, C. Chen, J. Xuan, and J.-J. Zhu. 2009. Enhanced electrochemiluminescence of CdSe quantum dots composited with CNTs and PDDA for sensitive immunoassay. Biosens. Bioelectron. 24 3352-3358. 

M. Danek, K.F. Jensen, C.B. Murray, M.G. Bawendi, Synthesis of luminescent thin film CdSe/ZnSe quantum dot composites using CdSe quantum dots passivated with an overlayer of ZnSe, Chem. Mater. 8 (1996)173-180. 

Clusters are intennediates bridging the properties of the atoms and the bulk. They can be viewed as novel molecules, but different from ordinary molecules, in that they can have various compositions and multiple shapes. Bare clusters are usually quite reactive and unstable against aggregation and have to be studied in vacuum or inert matrices. Interest in clusters comes from a wide range of fields. Clusters are used as models to investigate surface and bulk properties [2]. Since most catalysts are dispersed metal particles [3], isolated clusters provide ideal systems to understand catalytic mechanisms. The versatility of their shapes and compositions make clusters novel molecular systems to extend our concept of chemical bonding, stmcture and dynamics. Stable clusters or passivated clusters can be used as building blocks for new materials or new electronic devices [4] and this aspect has now led to a whole new direction of research into nanoparticles and quantum dots (see chapter C2.17). As the size of electronic devices approaches ever smaller dimensions [5], the new chemical and physical properties of clusters will be relevant to the future of the electronics industry. 

Nanoclusters/Polymer Composites. The principle for developing a new class of photoconductive materials, consisting of charge-transporting polymers such as PVK doped with semiconductor nanoclusters, sometimes called nanoparticles, Q-particles, or quantum dots, has been demonstrated (26,27). 

Electroluminescence from CdSe quantum dot / polymer composite. App/. Phys. Lett, 66,1316-1318. 

Recendy, ID quantum dots of gallium selenide with average diameter 8-10 nm, connected in the form of chains of average length 50-60 nm, were synthesized on rro substrates by cathodic electrodeposition from acidic aqueous solutions of gallium(III) nitrate and selenious acid [186], The structural analysis from XRD patterns revealed the formation of Ga2Se3/GaSe composition. The films were found to be photoactive in aqueous sodium thiosulfate solution and showed p-type conductivity. 

Research on semiconductor nanoparticle technology by chemists, materials scientists, and physicists has already led to the fabrication of a number of devices. Initially, Alivisatos and co-workers developed an electroluminescence device from a dispersion of CdSe nanoparticles capped with a conducting polymer349 and then improved on this by replacing the polymer with a layer of CdS, producing a device with efficiency and lifetime increased by factors of 8 and 10, respectively. 0 Chemical synthetic methods for the assembly of nanocrystal composites, consisting of II-VI quantum dot polymer composite materials,351 represent one important step towards the fabrication of new functional devices that incorporate quantum dots. 

The original polymeric latex particles still are widely used for separation and detection. Polymers provide a matrix that can be swollen for embedding other molecules in their core, such as organic dyes or fluorescent molecules. Even nanoparticle quantum dots can be incorporated into larger latex particles to form highly fluorescent composite microparticles. 

Narayanan, R., M. Deepa, and A.K. Srivastava, Nanoscale connectivity in a Ti02/CdSe quantum dots/functionalized graphene oxide nanosheets/Au nanoparticles composite for enhanced photoelectrochemical solar cell performance. Physical Chemistry Chemical Physics, 2012.14(2) p. 767-778. 

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