Abstract:
In this work, Organic Light Emitting diodes “OLEDS” optoelectronic properties are
investigated. These organic diodes are made of the polymer DP-PPV.
An in-depth study of the electrical and optical characteristics of bipolar monolayer and
two-layer organic light emitting diodes are presented. In the monolayer organic diodes, the
organic layer (P1, P2 or P3) is sandwiched between a semitransparent anode ITO/PEDOT: PSS
and a metallic cathode. As regards to the bi-layer organic diodes, two organic layers TFB and
(D1, D2 or D3) are sandwiched between a semitransparent anode ITO/PEDOT: PSS and a
metallic cathode.
The J-V characteristics, the charge balance factor CBF, the external quantum efficiency
EQE, the Langevin recombination rates and the singlet exciton densities profiles are investigated
using two different methods of simulation. The first one is based on a numerical computing in
Matlab by using a device model which includes the injection, transport, and recombination
mechanisms. The second one is based on the simulation of these characteristics by Atlas-Silvaco.
Electrical and optical characteristics obtained by modeling and simulation are found to be
in a good agreement with data obtained experimentally from literature. These results indicate
that an OLED’s good performance is guaranteed by the balance between injection and transport
mechanisms which is found in monolayer and bi-layer OLEDs. The results show also that adding
a second organic layer to the monolayer OLEDs improves greatly the different electrical and
optical properties.
