Open Access Nano Express

In situ growth of well-dispersed CdS nanocrystals in semiconducting polymers

Anna Maria Laera, Vincenzo Resta, Emanuela Piscopiello, Valerio Miceli, Monica Schioppa, Anna Grazia Scalone, Francesca Di Benedetto and Leander Tapfer*

Author Affiliations

ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy

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Nanoscale Research Letters 2013, 8:382  doi:10.1186/1556-276X-8-382

Published: 9 September 2013

Abstract

A straight synthetic route to fabricate hybrid nanocomposite films of well-dispersed CdS nanocrystals (NCs) in poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) is reported. A soluble cadmium complex [Cd(SBz)2]2·MI, obtained by incorporating a Lewis base (1-methylimidazole, MI) on the cadmium bis(benzyl)thiol, is used as starting reagent in an in situ thermolytic process. CdS NCs with spherical shape nucleate and grow well below 200°C in a relatively short time (30 min). Photoluminescence spectroscopy measurements performed on CdS/MEH-PPV nanocomposites show that CdS photoluminescence peaks are totally quenched inside MEH-PPV, if compared to CdS/PMMA nanocomposites, as expected due to overlapping of the polymer absorption and CdS emission spectra. The CdS NCs are well-dispersed in size and homogeneously distributed within MEH-PPV matrix as proved by transmission electron microscopy. Nanocomposites with different precursor/polymer weight ratios were prepared in the range from 1:4 to 4:1. Highly dense materials, without NCs clustering, were obtained for a weight/weight ratio of 2:3 between precursor and polymer, making these nanocomposites particularly suitable for optoelectronic and solar energy conversion applications.