How thermal environment affects OLEDs´ operational characteristics

In recent years great effort has been put into development of organic light emitting diodes (OLEDs) worldwide. Among many concerns of developers is heat-removal from the thin film structure of the active layers of OLEDs which are typically realized on low thermal conductivity substrates such as glass or polymer foils. The other issue is to provide the OLEDs with transparent, yet high electrical conductivity electric power supply structure, therefore metallic shunting grids are added to the layer stack of OLEDs. These two major issues necessitate self-consistent electro-thermal simulation of large area OLEDs in which the temperature dependent I-V characteristics of the light emitting polymer layers are also considered. In this paper we discuss details of our 2.5D field-solver algorithm extended with such capabilities which was developed for the European funded Fast2Light project. The paper also presents a measurement and simulation example for a glass-based research OLED sample.