Electrohydrodynamically Printed High‐resolution Arrays Based on Stabilized CsPbBr3 Quantum Dot Inks

Abstract High‐resolution perovskite quantum dots (PeQDs) arrays printed by electrohydrodynamic (EHD) inkjet printing show great application prospects in fields of micro‐display. Commonly, EHD inkjet requires a polar system for printing but it easily quenches the PeQDs. Meanwhile, the mismatch of solvent parameters causes uneven surface morphology and printing instability. In this work, a morphology uniformization strategy of a nonpolar binary solvent system of 1,3,5‐triethylbenzene and n‐tetradecane is proposed to prepare the didodecyldimethylammonium bromide (DDAB)/PbBr 2 passivated PeQDs inks. When the solvent volume ratio is 5:5, the photoluminescence quantum yield (PLQY) of the ink reaches 94.06%. Benefiting from the match of boiling point, surface tension, and dielectric constant of ink, after the EHD inkjet printing, the line width of continuous smooth line arrays is as narrow as 2.0 µm and the coffee effect of dot arrays is well inhibited. Meanwhile, derived from the strong electrostatic interaction between the π‐electron structure of 1,3,5‐triethylbenzene and DDA + , the ink exhibits high stability. Moreover, the high‐resolution logo and miniature quick responsecode by EHD inkjet printing reach 22 718 dpi, far higher than that of the reported micro‐LED. This work paves the way for high‐resolution pixel arrays of micro‐display.