Etude des propriétés électriques et optiques des diodes électroluminescentes organiques « OLED » à base de films minces en polymère.

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.