Inverted Quantum-Dot Light-Emitting Diodes Fabricated by All-Solution Processing

All-solution processed, multilayer, and inverted quantum-dot light-emitting diodes (QD-LEDs) are developed in this work. To protect the QDs from dissolving by the solvents of upper layers, the solvents of poly(9-vinlycarbazole) (PVK) hole transporting layer are first investigated. The QD layer has been less affected by o-dichlorobenzene solvent than other typical solvents like, chloroform and chlorobenzene. Second, to deposit a hydrophilic poly(ethylenedioxythiophene)/polystyrenesulfonate (PEDOT:PSS) hole injection layer on top of hydrophobic PVK, the surface energy of the PEDOT:PSS is reduced by using isopropanol as the additive. With optimized conditions, the demonstrated QD-LEDs exhibit a maximum luminance of 16290 cd/m(2) and a peak current efficiency of 4.1 cd/A, which is the highest among the reported values. These results may offer a practicable platform for further research, leading to the achievement of all-solution processed, multilayer, and efficient inverted QD-LEDs.