posted on 2018-08-27, 00:00authored byMarkus Regnat, Kurt P. Pernstich, Simon Züfle, Beat Ruhstaller
From s-polarized,
angle-dependent measurements of the electroluminescence
spectra in a three-layer phosphorescent organic light-emitting diode,
we calculate the exciton distribution inside the 35 nm thick emission
layer. The shape of the exciton profile changes with the applied bias
due to differing field dependencies of the electron and hole mobilities.
A split emission zone with high exciton densities at both sides of
the emission layer is obtained, which is explained by the presence
of energy barriers and similar electron and hole mobilities. A peak
in the transient electroluminescence signal after turn-off and the
application of a reverse bias is identified as a signature of a split
emission zone.