Origin of efficiency roll-off in colloidal quantum-dot light-emitting diodes

Publication Type:

Journal Article

Source:

Phys. Rev. Lett., APS, Volume 110, Issue 21, p.217403 (2013)

ISBN:

0031-9007

Keywords:

2013, 2013 and earlier

Abstract:

We study the origin of efficiency roll-off (also called "efficiency droop") in colloidal quantum-dot light-emitting diodes 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 light-emitting diodes.