  Surface plasmonic effects of metallic particles have been known to be an
effective method to improve the performance light emitting didoes. In this
work, we reported the sputtered Au nanoparticles enhanced electroluminescence
in inverted quantum dot light emitting diodes (ITO/Au
NPs/ZnMgO/QDs/TFB/PEDOT:PSS/Al). By combining the time-resolved
photoluminescence, transient electroluminescence and ultraviolet photoelectron
spectrometer measurements, the enhancement can be explained to the internal
field enhanced exciton coupling to surface plasmons and the increased electron
injection rate with Au nanoparticles incorporation. Phenomenological numerical
calculations indicated that the electron mobility of the electron transport
layer was increased from 1.39x10-5 to 1.91x10-5 cm2/V.s for Au NPs modified
devices. As a result, the maximum device luminescence is enhanced by 1.41 folds
from 14,600 to 20,720 cd/cm2 and maximum current efficiency is improved by 1.29
folds from 3.12 to 4.02 cd/A.
