Light‐Emitting Microinlaid Spots Produced through Lateral Phase Separation by Means of Simple Single‐Inkjet Printing. Issue 7 (9th May 2022)

• Record Type: Journal Article
• Authors: Park, Byoungchoo; Park, Jaewoo; Kim, Wonsun; Na, Seo Young; Huh, Yoon Ho; Kim, Mina; Choi, Eun Ha
• Is Part Of: Small science. Volume 2:Issue 7(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-09
• Subjects: convective and marangoni flows -- inkjet printing -- light-emitting devices -- microinlaid spots -- micropatterning -- microfluid flow-induced phase separation -- poly(4-vinylpyridine); Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.5
• DOI: 10.1002/smsc.202200017
• Languages: English
• ISSNs: 2688-4046

Abstract

Abstract : High‐performance solution‐processable light‐emitting diodes (LEDs) attract much research interest due to the very high complexity of conventional vacuum‐processed LEDs. A simple single‐inkjet‐printing process using a phase‐separable material combination is presented. With single‐inkjet printing of an ink containing semiconducting compounds on a phase‐separable insulating layer, convective and Marangoni flows in sessile droplets can produce microinlaid spots through the site‐selective etching of the insulating layer and the simultaneous self‐filling of the semiconductors in the etched vacancies. As a proof of concept, microinlaid organic LEDs (OLEDs) with a spatial resolution of ≈200 dpi in a phase‐separable poly(4‐vinylpyridine) layer without any conventional preformation of bank‐like structures are produced. The fabricated green microinlaid OLEDs exhibit excellent performance with maximum brightness of ≈13 000 cd m −2 and maximum efficiency of ≈14.2 cd A −1 . Moreover, large‐area inkjet‐printed OLEDs are simply realized using the microinlaid spot arrays. These results demonstrate that the inkjet‐inlay structure is a promising candidate for high‐performance next‐generation solution‐processable LEDs. Abstract : A light‐emitting inkjet‐inlaid spot is produced utilizing an appropriate material combination of a phase‐separable insulating polymer and functional semiconducting compounds for the simple and reliable fabrication of high‐performance small‐molecular micro‐organic light‐emitting diode (OLED) pixel arrays. Due to the self‐creation of high‐quality microinlaid spots, bright, efficient, and large‐area micro‐OLED pixel arrays are easily realized without any misalignment by the single‐inkjet‐printing process.