Scale-photo-electro-thermal model for organic light-emitting diodes

Organic light-emitting diodes (OLEDs) with large area have a great potential for lighting applications. The knowledge about scale, photometrical, electrical and thermal (SPET) domains of OLEDs is essential to achieve a good performance in lighting systems. This study presents an OLED model based on datasheet information and experimental tests to approach the interaction among SPET domains in OLED devices. The model is based on an equivalent electrical circuit that merges the electrical, thermal and photometrical behaviour of the OLED and that can easily be implemented in any computer-based simulation program. A detailed procedure for obtaining the different parameters of the proposed model is also presented in this study. The model has been verified for two different OLED geometries, with favourable agreement among theoretical, finite element analysis and experimental results. The results show the influence of scale factor on heat transfer mechanism and the temperature effect on electrical and photometrical OLED performance. This model is useful for predicting OLED behaviour and for simulating OLED drivers during the design of the lighting system.