Inkjet Printing of Luminescent CdTe Nanocrystal-Polymer Composites

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 libraries of CdTe NC–PVA composites with variable NC sizes and polymer/NC ratios are 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 to red‐light‐emitting CdTe NCs in the composite containing green‐ (2.6 nm diameter) and red‐emitting (3.5 nm diameter) NCs are demonstrated. Well‐defined dots and arrays composed of brightly emitting CdTe nanocrystals in a poly(vinylalcohol) (PVA) matrix are obtained using inkjet printing (see figure and inside cover). Dot uniformity is achieved using ethylene glycol–water as a solvent. The use of PVA as a matrix improves both the morphology and the emission properties of the printed nanocrystal films.