Electrothermal characterization of large-area organic light-emitting diodes employing finite-element simulation

We investigated and modeled the electrothermal behavior of a 5 × 5 cm2 organic light-emitting diode (OLED) with electrothermal measurements and finite-element simulation. A hybrid electrothermal model consisting of finite and lumped elements was proposed. Heat distribution of large-area OLED was measured by infrared spectroscopy. We have achieved an excellent agreement of measured and simulated results. The simulation confirms a strong influence of temperature on current distribution for large-area OLED. It turns out that the design of homogeneous devices requires knowledge about electrical and thermal aspects. Another result anticipates that the switching behavior of OLED strongly correlates with thermal relaxation. The model is a valuable tool to simulate luminance distribution and local aging allowing strong improvement of device development.

Excellent agreement of measured (a) and simulated (b) temperature distribution of an OLED.Figure optionsDownload as PowerPoint slideHighlights
► Excellent agreement of simulation and measurement.
► Demonstration and analysis of the influence of temperature towards OLED’s luminance homogeneity.
► Lateral geometry of an OLED influences luminance geometry.
► Thermal relaxation dominates switching behavior of an OLED.
► Simulation of an optimized OLED switching.