Conjugated Polymer and Luminescent Nanocrystals for Ink-Jet Printing

Nanocomposite solutions formed of Poly [(9,9-diesilfluorene)-(2,7 diyl)-alt-(2,5-dimetil-1,4-phenilene)] and highly luminescent nanocrystals of CdSe coated with a shell of ZnS (CdSe@ZnS) with different size have been obtained by using a common solvent and characterized by means of absorption and emission spectroscopy. Viscosity has been investigated, in order to prove the suitability of the inks for the printing processing. The homogeneous nanocomposites have been precisely dispensed by ink-jet printing, using drop-on-demand mode onto glass substrates. The deposited micro-scale pixels have been morphologically characterized by means of fluorescence microscopy, 3D profilometry and Atomic Force Microscopy (AFM). The results demonstrate that the spectroscopical properties of the components have been effectively conveyed to the final nanocomposites, retaining the size dependent feature of the inorganic moiety, and providing a suitable ink with for fabricating reproducible microstructures.