High-performance, high-resolution quantum dot light-emitting devices through photolithographic patterning

Abstract

We report here high-efficiency, high-resolution quantum dot (QD) light-emitting diodes patterned by ultraviolet-induced ligand exchange. A ligand passivation strategy is carried out to remove the surface defects of QDs after patterning, and thus the device efficiency shows more than 3-fold increase. Moreover, in order to reduce the leakage current occurring in the non-luminance area between QD arrays, a polymethyl methacrylate film is inserted as a charge barrier layer to separate the hole- and electron-transport layers from direct contact. As a result, the leakage current of the devices is effectively decreased. By optimizing the ligand passivation and synergistically suppressing the leakage current, the device with 5-μm diameter QD arrays exhibits luminance over 125000 cd/m 2 and maximum external quantum efficiency of 10.5%. This work provides a feasible way to achieving high resolution, high-performance quantum dot light-emitting diodes for next-generation display applications. • High-efficiency, high-resolution QLEDs patterned by lithography based on UV-induced ligand exchange. • New ligand passivation is employed to reinstate the robust emission of QDs. • The leakage current in the non-luminance area between the pixels was restrained by inserting a charge barrier layer.