Film formation properties of inkjet printed poly(phenylene-ethynylene)-poly(phenylene-vinylene)s

Inkjet printing was used here as a precise and fast dispensing technique to prepare thin-film libraries of a poly-(phenylene-ethynylene)-poly(phenylene-vinylene)s copolymer. The films were prepared with a systematic variation of the ink composition, the dot spacing and the substrate temperature. Homogeneous films with a thickness of 100 nm were obtained when printed at room temperature and from a solvent mixture of toluene and ortho-dichlorobenzene in a volume ratio of 90/10. This approach can be used for optoelectronic applications, where the layer homogeneity is extremely important but where the ink compositions may vary per device, as well as the exact layer thickness. Our approach can be applied for the preparation of films by inkjet printing for any other (polymer) ink solution and represents a fast and efficient screening of the parameters to obtain homogeneous films with a precise thickness.