Abstract
The aim of this work is to investigate the feasibility of coating and patterning of fine organic thin-film stripes using double nozzles. For fine stripe coating of an aqueous poly (3,4-ethylenedioxythiophene):poly (4-styrenesulfonate) (PEDOT:PSS), we have changed the outer surface of the needle from hydrophilic to hydrophobic in such a way that lateral capillary force is suppressed and thus the PEDOT:PSS stripe becomes narrow. Using a table coater with the hydrophobic needle (inner diameter = 51 μm), we have achieved the 54-μm-wide PEDOT:PSS stripe at a maximum coating speed of 30 mm/s. For micro patterning of PEDOT:PSS thin-film stripes, we have employed double needles; one for discharging the main solvent of the underlying thin film and the other for sucking the dissolved thin film. It is found that the pattern width decreases as the patterning speed increases and the pattern factor (the ratio of film thickness to slope length) is of the order of 10 −3 due to the isotropic patterning characteristics. Such a patterning scheme is also shown to remove non-aqueous poly (N-vinylcarbazole) (PVK) films coated in the presence of a bank structure. With the coating and patterning process, we have successfully fabricated multiple OLED stripes, an OLED device with the patterned light-emitting stripe, and OLED pixels, demonstrating its potential applicability to solution-processable OLEDs. • Suppressed lateral capillary flow by a hydrophobic needle for fine stripe coating. • Fabricated 54-μm-wide PEDOT:PSS stripe at a maximum coating speed of 30 mm/s. • Performed micro patterning of aqueous and non-aqueous thin films using double needles. • Achieved the pattern width of 260 μm and the pattern factor of 10 −3 using PEDOT:PSS. • Achieved light emission from OLED pixels and OLEDs with patterned or unpatterned stripes.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call