Dual-Ligand Red Perovskite Ink for Electrohydrodynamic Printing Color Conversion Arrays over 2540 dpi in Near-Eye Micro-LED Display

Abstract

The lack of stability of red perovskite nanocrystals (PeNCs) remains the main problem that restricts their patterning application. In this work, the dual-ligand passivation strategy was introduced to stabilize PeNCs and inhibit their halogen ion migration during high-voltage electrohydrodynamic (EHD) inkjet printing. The as-printed red arrays exhibit the highest emisson intensity and least blue shift compared with samples with other passivation strategies under a high electric field during EHD inkjet printing. Combining with blue and green PeNC inks, single-color and tricolor color conversion layer arrays were successfully printed, with minimum pixel size of 5 μm and the highest spatial resolution of 2540 dpi. The color coordinate of CsPbBrI 2 NCs arrays are located close to the red point, with a color gumat of 97.28% of Rec. 2020 standard. All of these show great potential in the application of color conversion layers in a near-eye micro-LED display.

Electrohydrodynamic Inkjet Printing of Three-Dimensional Perovskite Nanocrystal Arrays for Full-Color Micro-LED Displays

“…In addition, instead of mechanical movement, the ink injection and size control in EHD printing are adjusted by electric signals, which have room for higher accuracy and precision. To the best of our knowledge, there has so far been only a few reports on fabricating 3D micropillars via EHD inkjet printing in literature. − …”