LAUSR

Due to the inherent toxicity of cadmium selenide (CdSe)-based quantum dots (QDs), Cd-free alternatives are being widely investigated. Indium phosphide (InP) QDs have shown a great potential as a replacement for CdSe QDs in display applications. However the performances of InP based QLEDs is still far behind that of the CdSe-based devices. In this study, we investigated the effect of magnesium (Mg) doping in ZnO nanoparticles, which is used as n-type electron transport layer (ETL), in balancing the charge transfer in InP-based QLED devices. We found that increasing Mg doping level can broaden ZnO band gap and shift its energy levels; as a result, the electron current density is significantly reduced and the device efficiency is improved. Through optimizing QD structures and devices, red InP QLEDs with the current efficiencies as high as 11.6 cd/A were fabricated.