Year-end Sale % OFF 
Abstract
With an attempt to achieve high-density fine organic stripes for potential applications in solution-processable organic light-emitting diodes (OLEDs), we have performed slot-die coatings using a shim with slit channels in various shapes (rectangular-shaped narrow, rectangular-shaped wide, and reversely tapered channels) in the presence of narrow µ-tips. Based on hydraulic-electric circuit analogy, we have analyzed the fluid dynamics of an aqueous poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (PEDOT:PSS). It is observed that the coating speed can be increased and the stripe width can be reduced using a shim with rectangular-shaped wide slit channels. It is attributed that the hydraulic resistance is decreased and thus more fluid can reach a substrate through µ-tips. This behavior is consistent with the simulation result of the equivalent electrical circuit with a DC voltage source representing a pressure source. Using the shim with 150-µm-wide slit channels, we have successfully fabricated 200 PEDOT:PSS stripes within the effective coating width (150 mm) and 160 OLED stripes (34 stripes per inch) with the luminance of 325 cd/m2 at 5 V.
Highlights
Due to a simple process, low material loss, and scalability to large-area manufacturing, printing and coating processes have attracted much attention for the fabrication of organic light-emitting diode (OLED) display panels [1,2], organic light-emitting diodes (OLEDs) lightings [3,4,5], solar cells [6,7], sensors [8,9], batteries [10,11], etc.Printing processes have been employed to fabricate the emission layers of OLEDs, which require fine patterning
The meniscus guide is protruded from the head lip in order to control the meniscus [36]. Such a meniscus guide together with a shim was first employed to fabricate wide stripes having a centimeter width required for solar cells [37,38]. We explored this scheme in OLEDs and demonstrated that thin-film stripes of poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (PEDOT:PSS) having a micrometer width could be fabricated by the slot-die head with protruded μ-tips [39,40,41]
In order to study the effect of the slit channel configuration on the fluid dynamics and thin-film properties, we first performed single stripe coatings
Summary
Due to a simple process, low material loss, and scalability to large-area manufacturing, printing and coating processes have attracted much attention for the fabrication of organic light-emitting diode (OLED) display panels [1,2], OLED lightings [3,4,5], solar cells [6,7], sensors [8,9], batteries [10,11], etc.Printing processes (e.g., inkjet [12,13], gravure [14,15], nozzle [16,17], etc.) have been employed to fabricate the emission layers of OLEDs, which require fine patterning. Coating processes (e.g., blade, spin, spray, slot, etc.) have been utilized to fabricate the blanket (common) layers of OLEDs, which require large-area uniform films [3,5]. The coating process has the opposite characteristics to the printing process It enables coating of a wide range of process materials (low- and high-viscosity solutions). Spray coating has a high roll-to-roll (R2R) compatibility, but requires a mask for patterning, thereby degrading edge resolution [24,25,26]. Slot-die coating is compatible with both R2R and sheet-to-sheet deposition processes [27,28]. It enables simultaneous multilayer formation, yielding a discrete bilayer film [29]. The coating speed had the most influence on Coatings 2020, 10, 772; doi:10.3390/coatings10080772 www.mdpi.com/journal/coatings
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
