Paper No S10.3: Efficiency Enhancement of InP-Based Inverted QD-LEDs by Polyethylenimine-Modified Al:ZnO Layer

In this paper, we report efficiency enhancement of indium phosphide (InP) quantum dot-based light-emitting diodes (QD-LEDs) using polyethylenimine (PEI) surface modifier. Adapting solution processed PEI layer on top of the aluminum-doped zinc oxide (Al:ZnO) nanoparticle (NP) layer, the leakage current of inverted device was suppressed and electron injection into conduction band of InP/ZnSe/ZnS QDs also facilitated by interfacial dipoles of thin PEI layer. As a results, the current efficiency was dramatically increased from 0.07 cd/A to 2.84 cd/A.