The main constitutive difference concern materials: OLEDs are made of mainly organic materials, whereas conventional LEDs are made of inorganic and metal-containing materials.
The performances of OLEDs, in terms of efficiency, life-time and luminance, are at the moment lower than in conventional LEDs. However, OLEDs emit light on a surface, whereas LEDs are point light sources. The nature of the emitted light in OLEDs (softer and more diffuse) enables then novel applications in several fields. In addition, the use of organic materials in OLEDs allow to realize flexible and low-cost light-emitting sources.