Inkjet printing of luminescent CdTe nanocrystal-polymer composites

Inkjet printing is used to produce well-defined patterns of dots (with diams. of ca. 120 mm) that are composed of luminescent CdTe nanocrystals (NCs) embedded within a poly(vinylalc.) (PVA) matrix. Addn. of ethylene glycol (1-2 vol%) to the aq. soln. of CdTe NCs suppresses the well-known ring-formation effect in inkjet printing leading to exceptionally uniform dots. At. force microscopy characterization reveals that in the CdTe NC films the particle-particle interaction could be prevented using inert PVA as a matrix. Combinatorial libraries of CdTe NC-PVA composites with variable NC sizes and polymer/NC ratios are prepd. using inkjet printing. These libraries are subsequently characterized using a UV/fluorescence plate reader to det. their luminescent properties. Energy transfer from green-light-emitting to red-light-emitting CdTe NCs in the composite contg. green- (2.6 nm diam.) and red-emitting (3.5 nm diam.) NCs are demonstrated.