Colloids and Surfaces A: Physicochemical and Engineering Aspects 163 (2000) 39 – 44 Formation of luminescent spherical core-shell particles by the consecutive adsorption of polyelectrolyte and CdTe(S) nanocrystals on latex colloids Andrei S. Susha a,1 , Frank Caruso a, *, Andrey L. Rogach 1b , Gleb B. Sukhorukov a , Andreas Kornowski b , Helmuth Mo ¨ hwald a , Michael Giersig c , Alexander Eychmu ¨ ller b , Horst Weller b a Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany b Institute of Physical Chemistry, Uniersity of Hamburg, 20146 Hamburg, Germany c Hahn -Meitner -Institute, Glienicker Strasse 100, D-14109 Berlin -Wannsee, Germany Abstract Functional core-shell particles were prepared by assembling a composite multilayer shell of charged polyelectrolytes and luminescent CdTe(S) nanocrystals (cadmium telluride with a certain content of sulfide) via their consecutive electrostatic adsorption from solution onto micron-sized latex particles. The formation of the composite shell has been confirmed by optical spectroscopy, confocal microscopy and high-resolution transmission electron microscopy. Variation of the size and surface chemistry of the semiconductor nanoparticles, the size and shape of the colloid templates, and the nature of the polyelectrolyte opens new avenues for the production of a variety of novel core-shell materials. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Polyelectrolyte; Semiconductor; Nanoparticle; Core-shell; Luminescence www.elsevier.nl/locate/colsurfa 1. Introduction In the last decade semiconductor nanocrystals have become the subject of investigation in one of the most rapidly growing branches of chemistry and physics. They belong to a state of matter lying in the transition regime between molecules and bulk materials. Due to the quantum confi- nement effect, nanocrystals show unique physical and chemical properties, such as size-dependent bandgap shifts, size – dependent ‘excitonic’ photo- luminescence, and enhanced nonlinear optical properties when their size becomes smaller than the dimension of the bulk exciton [1]. Achieve- ments made by chemists in the synthesis of high- quality nanoparticles and by physicists in their characterization allow a transition from pure ba- sic research to applications of nanomaterials in electrical and optoelectronic devices [2]. * Corresponding author. Tel.: +49-331-5679410; fax: +49- 331-5679202. E-mail address: frank.caruso@mpikg-golm.mpg.de (F. Caruso) 1 Present address: Physico-Chemical Research Institute, Be- larusian State University, 220050 Minsk, Belarus. 0927-7757/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII:S0927-7757(99)00428-8