2, The University of Seoul, Seoul, , Korea (the Republic of)
Quantum dot (QD) light-emitting diodes (QLEDs) emerge as a new device for flat-panel displays with superior qualities, such advantages as a narrow emission spectrum (high color purity), colloidal stability, and low cost solution processibility. Since the first demonstration of the efficient QLED, intensive researches have been carried out to improve the device performance such as luminous efficiency, a driving voltage and a lifetime. However, fewer researches on the degradation mechanism of QLEDs have been reported than their efficiency or driving voltages. In this work, we investigated the effect of degradation in the red-emitting QLEDs with an inverted structure of ITO/ZnO/QD/CBP/MoO3/Al by using an impedance spectroscopy with the applied external electric field. Both the electroluminescence characteristics and the analysis of the charge variation inside the devices before and after constant current aging will be presented.