Enhanced thermal stability of green-emission quantum-dot light-emitting diodes via composition-gradient thick-shell quantum dots

We investigated the thermal properties of quantum-dot light-emitting diodes (QLEDs) using composition-gradient thick-shell CdSe@ZnS/ZnS QDs. Thick-shell QDs with low defective structures effectively prevented electron-hole pairs from nonradiative Auger recombination. More specifically, defects were prevented from thermal-stress-induced expansion at elevated temperatures and high driving currents. Consequently, 97% of EL remained after the device was thermally stressed at temperatures higher than 110 degrees C, indicating that the nanostructure design of QDs is an important factor for high-performance QLEDs. (C) 2016 The Japan Society of Applied Physics