Surfactant-mediated variation of band-edge emission in CdS nanocomposites
O'Dwyer, Colm; Lavayen, Vladimir; Mirabal, Neisy; Santa-Ana, María A.; Benavente, Eglantina; Ormazabal, S.; Gonzalez, Guillermo; Lopez, Z.; Schöps, O.; Woggon, U.; Sotomayor Torres, Clivia M.
Date:
2007-08-03
Copyright:
© 2007 Elsevier B.V. All rights reserved. This manuscript version is made available under the CC-BY-NC-ND 4.0 license.
Citation:
O'Dwyer, C., Lavayen, V., Mirabal, N., Santa Ana, M. A., Benavente, E., Ormazabal, S., Gonzalez, G., Lopez, Z., Schöps, O., Woggon, U. and Sotomayor Torres, C. M. (2007) 'Surfactant-mediated variation of band-edge emission in CdS nanocomposites', Photonics and Nanostructures - Fundamentals and Applications, 5(2-3), pp. 45-52. http://www.sciencedirect.com/science/article/pii/S1569441007000284
Abstract:
The optical-structural characteristics of the direct optical band-gap semiconducting series of surfactant template-mediated laminar (CdS)x(CdCl2)y(CnH2n+4N)z nanocomposites are reported. X-ray diffraction measurements of the nanocomposites exhibited interlaminar distances in the range 2.9-3.6 nm with observations of eighth order {0 0 l} diffraction planes indicative of a high degree of laminarity and crystallographic order. Diffuse reflectance measurements have determined that the profile of their emission spectrum is that of a direct band-gap with absorption edges in the range 2.11-2.40 eV, depending on the CdS mole fraction in the nanocomposite. Photoluminescence (PL) excitation and time-resolved PL spectroscopies give an estimate of the maximum relative absorbance of the nanocomposites at ∼420 nm while the minimum was observed at ∼560 nm. The main emission was observed at ∼700 nm with emission from doubly ionized sulphur vacancies observed at ∼615 nm at room temperature. The CdS-containing nanocomposite is thus a surfactant-mediated modular system with variable band-gap energy emission.
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