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. − …”

Multiparticle Synergistic Electrophoretic Deposition Strategy for High-Efficiency and High-Resolution Displays

“…To precisely define the arrangement and spacing of multiparticles for consistent and uniform performance, directed assembly has been developed, which utilizes external fields such as electric, magnetic, optical, and fluid flow to drive the NPs to site-selectively assemble in patterned areas on substrates. − Electrophoretic deposition (EPD), as one of the electrically driven assembly technologies, has the inherent capability to control the regular assembly of multiple particles. The technique is cost-effective, requiring simple equipment and a short formation time.…”

Efficient Large-Area Quantum Cutting Photoconversion Films for Silicon Solar Cells on Photovoltaic Glass Using Knife Coating

“…Besides lattice defects, PNCs exhibit numerous surface defects resulting from the detachment of oleic acid (OA) or oleylamine (OLA) ligands. , These defects significantly compromise surface integrity and the stability of the PNCs’ optical–electrical properties, leading to a notable decrease in their PLQY upon deposition into thin films and diminished photoconversion. Passivating PNCs with short-chain functional ligands, such as bidentate ligands, thiocyanates, or fluoroborates, is a common method to improve film quality. − X-type ligands cysteine with a functional group resembling those of PNCs (RCOO – and RNH 3 + ) provide a viable alternative to the commonly used OA/OLA ligands on pristine PNCs, making them promising candidates for short-chain passivation. , Moreover, cysteine’s unique sulfhydryl group can form Pb–S bonds with surface-exposed Pb 2+ ions on PNCs, efficiently passivating their defects . Encouragingly, preparation of large-area photoconversion films may involve selecting suitable impurity ions for doping to modify PNCs’ lattice defects and then combining them with passivators to create high-quality, high-PLQY photoconversion films.…”