Tuesday, 02 January, 2007
Inkjet Printing of Luminescent CdTe Nanocrystal-Polymer Composites
E. Tekin, P.J. Smith, S. Hoeppener, A.M.J. van den Berg, A.S. Susha, A.L. Rogach, J. Feldmann, U.S. Schubert -
Adv. Funct. Mater. 17, 2328 (2007)
Inkjet printing is used to produce well-defined patterns of dots (with diameters of ca. 120 µm) that are composed of luminescent CdTe nanocrystals (NCs) embedded within a poly(vinylalcohol) (PVA) matrix. Addition of ethylene glycol(1-2 vol %) to the aqueous solution of CdTe NCs suppresses the well-known ring-formation effect in inkjet printing leading to exceptionally uniform dots. Atomic force microscopy characterization reveals that in the CdTe NC films the particle-particle interaction could be prevented using inert PVA as a matrix. Combinatorial librariesof CdTe NC-PVA composites with variable NC sizes and polymer/NC ratiosare prepared using inkjet printing. These libraries are subsequently characterized using a UV/fluorescence plate reader to determine their luminescent properties. Energy transfer from green-light-emitting tored-light-emitting CdTe NCs in the composite containing green- (2.6 nmdiameter) and red-emitting (3.5 nm diameter) NCs are demonstrated.