Controlled Growth of CdS Nanocrystals: Core/Shell viz Matrix
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Abstract
The ability to precisely control the size of semiconductor nanocrystals can create an opportunity for producing functional materials with new properties, which are of importance to applications such as Light emitting diodes, biomedical diagnosis, solar cells, and spintronics. And size of nanoparticle can be controlled with efficient capping agent. For the same purpose we reported, two types of capping, one will lead to nanomatrix and other to Shelled nanostructures. Enhancement in emission intensity observed with Shell nanostructures compare to matrix. PVP is used to control the particle size, to prevent agglomeration and making thin films. A blue shift in energy level at the nanoscale is demonstrated by optical absorption. Electron microscopy studies with an SEM and TEM show a particle size of 10 nm and 15 nm. We also investigated the particle size distribution of nanoparticles by small angle scattering (SAXS) study.
- N. Herron, Y.Wang and H.Eckert, “Synthesis and Characterization of Surface-Capped, Size-Quantized CdS Clusters. Chemical Control of Cluster Size,” J. Amer. Chem.Soc, Vol. 112, 1990, pp. 1322-1326 .
- Y. Wang and N. Herron, “Nanometer-Sized Semiconductor Clusters: Materials Synthesis, Quantum Size Effects, and Photophysical Properties,” J. Phys. Chem, Vol. 95, 1991, pp. 525 -532.
- L.E Brus, “A Simple Model for the Ionization Potential, Electron Affinity, and Aqueous Redox Potentials of Small Semiconductor Crystallites,’’ J. Chem. Phys. Vol. 79, 1983, pp. 5566-5571.
- Manoj Nirmal and Louis Brus, “Luminescence Photophysics in Semiconductor Nanocrystals,” Acc. Chem.Res, Vol. 32, 1999, pp. 407-414.
- M. Kundu, A.A. Khosravi, S.K. Kulkarni and P.Singh, “Synthesis and study of organically capped ultra small clusters of cadmium sulphide,” J. Mater. Sci, Vol. 32, 1997, pp. 245-258.
- Xiaobo Chen, Yongbing Lou and Clemens Burda, “Spectroscopic Characterization of II-VI Core-Shell Nanoparticles CdSe/CdS, ”Int. J. of Nanotechnology, Vol. 1, 2004, pp. 105-118.
- S.K Kulkarni, U. Winkler, N Deshmukh, P.H Borse, R. Fink, E. Umbach, “Investigations on chemically capped CdS, ZnS and ZnCdS nanoparticles,” Applied Surface Science, Vol. 169 , 2001, pp. 438-446.
- B. Saraswathi Amma, K. Manzoor, K. Ramakrishna, Manjunatha Pattabi , “Synthesis and optical properties of CdS/ZnS coreshell nanoparticles,” Materials Chemistry and Physics, Vol. 112, 2008, pp. 789-792.
- YanDan Wuab, LiShi Wang, “A novel sonochemical synthesis and nanostructured assembly of polyvinylpyrrolidone-capped CdS colloidal nanoparticles,”J. of Non- Crystalline Solids, Vol. 354, 2008, pp. 2993-3000.
- X.G. Peng, M.C. Schlamp, A.V. Kadavanich, A.P. Alivisatos, “Epitaxial growth of highly luminescent CdSe/CdS core/shell nanocrystals with photostability and electronic accessibility,” J.of the American Chemical Society, Vol. 30 , 1997, pp. 7019-7029.
- B.S. Zou, R.B. Little, J.P. Wang, M.A. El-Sayed, “Effect of different capping environments on the optical properties of CdS nanoparticles in reverse micelles,” Int. J. Quantum Chem, Vol. 72, 1999, pp. 439-450.
- M.A. Hines, P. Guyot-Sionnest, “Synthesis and Characterization of Strongly Luminescing ZnS-Capped CdSe Nanocrystals,” J. Phys. Chem, Vol. 100, 1996, pp.468- 471.
- A. Eychmuller, A. Hasselbarth, L. Katsikas, H.Weller, “Fluorescence mechanism of highly monodisperse Q- sized CdS colloids,” J. of Lumin, Vol.745, 1991, pp. 48-49.