Solution-processed high-efficiency cadmium-free Cu-Zn-In-S-based quantum-dot light-emitting diodes with low turn-on voltage

High-efficiency green, yellow and red quantum-dot light emitting devices (QLEDs) have been fabricated via a simple solution-processed technique, in which different-colored Cu-In-Zn-S/ZnS core/shell colloidal semiconductor nanocrystals (NCs) are used as emissive layers sandwiched between an organic holes transport layer and an electron transport layer of ZnO nanoparticles. The yellow QLEDs exhibit a low turn-on voltage of 1.8 V and high luminance of 3061 cd/m(2) as well as the peak external quantum efficiency (EQE) of 2.42%. In contrast, the green and red QLEDs show a low turn-on voltage of 2 V, and their electroluminescence (EL) peaks are located at 540 and 642 nm with the peak EQE of 0.25% and 0.91%, respectively. The solution-processed high-efficiency cadmium-free QLEDs with a low turn-on voltage and good reproducibility may become one of the most promising next generation of display. (C) 2016 Elsevier B.V. All rights reserved.