Origin of efficiency roll-off in colloidal quantum-dot light-emitting diodes
Yasuhiro Shirasaki, Geoffrey J. Supran, William A. Tisdale, and Vladimir Bulović
Accepted
We study the origin of efficiency roll-off (also called ���efficiency droop���) in colloidal quantum-dot LEDs through the comparison of quantum-dot (QD) electroluminescence and photoluminescence. We find that an electric-field-induced decrease in QD luminescence efficiency ��� and not charge leakage or QD charging (Auger recombination) ��� is responsible for the roll-off behavior, and use the quantum confined Stark effect to accurately predict the external quantum efficiency roll-off of QD-LEDs.