Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-23T09:02:10.121Z Has data issue: false hasContentIssue false

Study on precipitation efficiency of solvents in postpreparative treatment of nanocrystals

Published online by Cambridge University Press:  14 October 2013

H.R. Chandan*
Affiliation:
Centre for Nano and Material Sciences, Jain Global Campus, Jain University, Bangalore Rural-562112, India
Balakrishna R. Geetha*
Affiliation:
Centre for Nano and Material Sciences, Jain Global Campus, Jain University, Bangalore Rural-562112, India
*
a)Address all correspondence to this author. e-mail: geethabalakrishna@yahoo.co.in
Get access

Abstract

High quality CdSe nanocrystals (NCs) were synthesized via a nonorganometallic precursor and extracted in different solvents. The difference in the influence of the nature of the solvent namely ethanol, N,N-dimethyl formamide (DMF), and acetonitrile on extraction of the same type of NCs was studied with respect to quality and stability of NCs. Characterization by x-ray diffraction technique, absorption–emission spectroscopy, scanning, transmission, and atomic force microscopy demonstrated the formation of NCs of good optical property and surface composition from the synthesis method used. Different polarities of the solvent strongly influence photoluminescence (PL), surface defects, concentrations of NCs extracted, particle sizes, and surface passivation. Ethanol extraction results in small-sized NCs and good particle size distribution. DMF extraction causes lesser interfacial defects and hence prevents radiative recombinations. PL quenching was observed in all the three solvents, and this necessitates further stabilization of NCs. The stability of the so-extracted NCs was evaluated for change in their properties with respect to aging. Aging substantiated the adverse effects of acetonitrile to extract the lesser surface passivated NCs leading to Ostwald ripening and island formation. The phase and structure of NCs remain unaffected with aging or by the nature of solvent used.

Type
Articles
Copyright
Copyright © Materials Research Society 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Newton, J.C., Ramaswamy, K., Mandal, M., Joshi, G.K., Kumbhar, A., and Sardar, R.: Low temperature synthesis of magic sized Cdse nanoclusters: Influence of ligands on nanocluster growth and photophysical properties. J. Phys. Chem. C 116, 4380 (2012).CrossRefGoogle Scholar
Murcia, M.J., Shaw, D.L., Woodruff, H., Naumann, C.A., Young, B.A., and Long, E.C.: Facile sonochemical synthesis of highly luminescent ZnS-shelled CdSe quantum dots. Chem. Mater. 18, 2219 (2006).CrossRefGoogle Scholar
Luan, W., Yang, H., Fan, N., and Tu, S-T.: Synthesis of efficiently green luminescent Cdse/Zns nanocrystals via microfluid reaction. Nanoscale Res. Lett. 3, 134 (2008).CrossRefGoogle Scholar
Williams, J.V., Adams, C.N., Kotov, N.A., and Savage, P.E.: Hydrothermal synthesis of CdSe nanoparticles. Ind. Eng. Chem. Res. 46, 4358 (2007).CrossRefGoogle Scholar
Kang, B., Chang, S-Q., Dai, Y-D., and Chen, D.: Synthesis of green Cdse/Chitosan quantum dots using a polymer assisted-radiation route. Radiat. Phys. Chem. 77, 853 (2008).CrossRefGoogle Scholar
Efros, A.L. and Efros, A.L.: Interband absorption of light in a semiconductor sphere. Sov. Phys. Semicond. 16, 772 (1982).Google Scholar
Brus, L.E.: Electronic wavefunctions in semiconductor clusters: Experiment and theory. J. Phys. Chem. 90, 2555 (1986).CrossRefGoogle Scholar
Wang, Y. and Herron, N.: Nanometer-sized semiconductor clusters: Materials synthesis, quantum size effects, and photophysical properties. J. Phys. Chem. 95, 525 (1991).CrossRefGoogle Scholar
Alivisatos, A.P.: Semiconductor clusters, nanocrystals, and quantum dots. Science 271, 933 (1996).CrossRefGoogle Scholar
Babentsov, V., Riegler, J., Schneider, J., Ehlert, O., Nann, T., and Fiederle, M.: Deep level defect luminescene in cadmium selenide nano-crystals films. J. Cryst. Growth 280, 502 (2005).CrossRefGoogle Scholar
Troparevsky, M.C. and Franceschetti, A.: Radiative recombination of charged excitons and multiexcitons in CdSe quantum dots. Appl. Phys. Lett. 87, 263115 (2005).CrossRefGoogle Scholar
Lopez-Luke, T., Wolcott, A., Xu, L-P., Chen, S., Wen, Z., Li, J., De La Rosa, E., and Zhang, J.Z.: Nitrogen doped and CdSe quantum dot-sensitized nanocrystalline TiO2 films for solar energy conversion application. J. Phys. Chem. C 112, 1282 (2008).CrossRefGoogle Scholar
Kongkanand, A., Tvrdy, K., Takechi, K., Kuno, M., and Kamat, P.V.: Quantum dot solar cells. Tuning photoresponse through size and shape control of CdSe-TiO2 architecture. J. Am. Chem. Soc. 130, 4007 (2008).CrossRefGoogle ScholarPubMed
Vega Macotela, L.G., Torchynska, T.V., Douda, J., Pena Sierra, R., and Shcherbyna, L.: Radiative interface state study in CdSe/ZnS quantum dots covered by polymer. Mater. Sci. Eng., B 176, 1349 (2011).CrossRefGoogle Scholar
Murray, C.B., Norris, D.J., and Bawendi, M.G.: Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallites. J. Am. Chem. Soc. 115, 8706 (1993).CrossRefGoogle Scholar
William Yu, W., Qu, L., Guo, W., and Peng, X.: Experimental determination of excitation co-efficient of CdTe, CdSe, and CdS nanocrystals. Chem. Mater. 15, 2854 (2003).Google Scholar
van Embden, J. and Mulvaney, P.: Nucleation and growth of CdSe nanocrystals in a binary ligand system. Langmuir 21, 10226 (2005).CrossRefGoogle Scholar
Merz, J.L., Lee, S., and Furdyna, J.K.: Self organized growth, ripening, and optical properties of wide bandgap II-VI quantum dots. J. Cryst. Growth 184185, 228 (1998).Google Scholar
Peng, X., Wickham, J., and Alivistatos, A.P.: Kinetics of II-V colloidal semiconductor nanocrystal growth: Focusing of size distribution. J. Am. Chem. Soc. 120, 5343 (1998).CrossRefGoogle Scholar
Murray, C.B., Kagan, C.R., and Bawendi, M.G.: Synthesis and characterization of monodisperse nanocrystals and close packed nanocrystal assemblies. Annu. Rev. Mater. Sci. 30, 545 (2000).CrossRefGoogle Scholar
Jasieniak, J., Bullen, C., van Embden, J., and Mulvaney, P.: Phosphine-free synthesis of CdSe nanocrystals. J. Phys. Chem. B 109, 20665 (2005).CrossRefGoogle ScholarPubMed
Lee, J.R.I., Whitley, H.D., Meulenberg, R.W., Wolcott, A., Zhang, J.Z., Prendergast, D., Lovingood, D.D., Strouse, G.F., Ogitsu, T., Schwegler, E., Terminello, L.J., and van Buuren, T.: Ligand mediated modification of electronic structure of CdSe quantum dots. Nano Lett. 12, 276 (2012).Google ScholarPubMed
Li, Z. and Peng, X.: Size/shape controlled synthesis of colloidal CdSe quantum disks: Ligand and temperature effects. J. Am. Chem. Soc. 133, 6578 (2011).CrossRefGoogle ScholarPubMed