Electrospray mechanism for quantum dot thin-film formation using an electrohydrodynamic jet and light-emitting device...

A novel electrohydrodynamic (EHD) electrospray coating mechanism was proposed for the continuous fabrication of large-area quantum dot (QD) thin films for high-performance light-emitting diodes (LEDs). The size of QD droplets was systemically controlled using the stable EHD electrospray mode from a mixed solvent, which is a crucial factor for the formation of large and smooth QD thin films. The minimum amount of material consumption was achieved during the process by applying the unique coating system. A QD-LED device based on electrodeposited QDs showed a maximum luminance of 12,082 cd m^-2, maximum current efficiency of nearly 4.0 cd A^-1, and maximum EQE of 1.86%. This system demonstrates not only high reproducibility but could also pave the way for commercializing high-quality QD-LED devices.