High-Resolution Inkjet Printing of Quantum Dot Light-Emitting Microdiode Arrays


The direct printing of microscale quantum dot light-emitting diodes (QLEDs) is a cost-effective alternative to the placement of pre-formed LEDs. The quality of printed QLEDs currently is limited by nonuniformities in droplet formation, wetting, and drying during inkjet printing. Here, optimal ink formulation which can suppress nonuniformities at the pixel and array levels is demonstrated. A solvent mixture is used to tune the ejected droplet size, ensure wetting, and provoke Marangoni flows that prevent coffee stain rings. Arrays of green QLED devices are printed at a resolution of 500 pixels in.−1 with a maximum luminance of ≈3000 cd m−2 and a peak current efficiency of 2.8 cd A−1. The resulting array quality is sufficient to print displays at state-of-the-art resolutions.

high resolution, inkjet printing, light-emitting diodes, quantum dots, uniform pixel arrays, Cost effectiveness, Drops, Ink jet printing, Light emitting diodes, Nanocrystals, Pixels, Semiconductor quantum dots, Wetting, Droplet formation, High resolution, Maximum luminance, Non-uniformities, Pixel arrays, Quantum-dot light emitting diodes, Solvent mixtures, State of the art, Organic light emitting diodes (OLED)
Yang, P., Zhang, L., Kang, D. J., Strahl, R., & Kraus, T. (2020). High-Resolution Inkjet Printing of Quantum Dot Light-Emitting Microdiode Arrays (Version publishedVersion, Vol. 8). Version publishedVersion, Vol. 8. Weinheim : Wiley-VCH Verlag. https://doi.org//10.1002/adom.201901429