title: Electric field directed layer-by-layer assembly of highly fluorescent CdTe nanoparticles.
abstract: An electric field directed layer-by-layer assembly technique has been developed by combining electrophoretic deposition and the layer-by-layer self-assembly method. This technique is employed to realize spatially selective deposition of CdTe nanoparticles on electrodes of indium-tin oxide (ITO). The fluorescence measurements prove that the selectivity of the film deposition increases against applied voltage and reaches 99% when the voltage is 1.4 V. Upon further increase of the voltage, the selectivity slightly decreases. This decrease occurs because high voltage leads to a degradation of CdTe particles and thus reduces fluorescence intensity of the resultant CdTe film. However, fluorescence investigation indicates that a spacer layer of polyelectrolyte complex between the ITO electrode and the CdTe film is useful to protect the CdTe from being destroyed under high voltages.
authors.affiliation: Department of Physics, Center of Nanoscience, University of Munich, Amalienstrasse 54, D-80799 Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: M
authors.initials: M
authors.lastname: Gao
authors.forename: J
authors.initials: J
authors.lastname: Feldmann
mesh_terms: D000643:Ammonium Chloride; D019187:Cadmium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004574:Electromagnetic Fields; D004586:Electrophoresis / Q000379:methods*; D004867:Equipment Design; D005453:Fluorescence; D008422:Materials Testing; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D010777:Photochemistry / Q000295:instrumentation / Q000379:methods; D011095:Polyethylenes / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry / Q000302:isolation & purification; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D017971:Tin Compounds; D000643:Ammonium Chloride; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; C109984:indium tin oxide; D013691:Tellurium; C028337:cadmium telluride