Open AccessLight‐Emitting Microinlaid Spots Produced through Lateral Phase Separation by Means of Simple Single‐Inkjet Printing
Author(s) -
Park Byoungchoo,
Park Jaewoo,
Kim Wonsun,
Na Seo Young,
Huh Yoon Ho,
Kim Mina,
Choi Eun Ha
Publication year - 2022
Publication title -
small science
Language(s) - English
Resource type - Journals
ISSN - 2688-4046
DOI - 10.1002/smsc.202200017
Subject(s) - materials science , optoelectronics , oled , layer (electronics) , light emitting diode , inkwell , diode , etching (microfabrication) , brightness , phase (matter) , nanotechnology , optics , composite material , chemistry , physics , organic chemistry
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.