Scalable Fabrication of Patterned Green Perovskite Quantum-Dot Light-Emitting Diodes via Electrohydrodynamic Printing with Halogen-Free Binary Ink and Interface Optimization

Abstract

Halide perovskite quantum dots (PeQDs) have emerged as compelling emissive materials for next-generation displays owing to their narrow emission linewidths and high photoluminescence quantum yields (PLQYs). However, their limited environmental stability and the requirement for strictly controlled inert atmospheres during fabrication remain significant barriers to practical deployment. In this study, we present the scalable fabrication of green-emitting perovskite quantum-dot light-emitting diodes (PeQD-LEDs) via electrohydrodynamic (EHD) jet printing performed entirely under ambient air conditions. A carefully engineered halogen-free binary solvent ink—consisting of decalin and n-tridecane at a 7:3 volume ratio—was employed to suppress coffee-ring formation through an inward Marangoni flow, ensuring stable jetting behavior. Notably, the EHD-printed devices exhibited performance metrics highly comparable to conventional spin-coated reference devices. While the EHD-printed PeQD-LEDs showed a slight shift toward a higher turn-on voltage and a lower current density due to the increased thickness of the printed emissive layer, the peak luminance and efficiency values remained largely consistent. Specifically, the air-processed EHD devices achieved a maximum luminance exceeding 11,600 cd/m2 and a peak current efficiency (CE) of approximately 5.0 cd/A, proving that our ink−interface codesign effectively facilitates comparable carrier injection. The successful demonstration of uniform PeQD-LEDs under ambient air points toward the possibility of a robust and industrially relevant manufacturing route for high-resolution displays without the need for an expensive inert-gas infrastructure.