Technology

What is an OLED and how does it generate light?

All common LEDs use inorganic semiconductor materials (i.e. Gallium Aresenide or GaAs) to generate light. The physical effect used is called electroluminescence meaning that certain materials can emit visible light when stimulated by an electric current. An OLED (Organic Light Emitting Diode) uses the same effect with the major difference that the used materials are hydro carbonate compounds – labelled “organic” because they are the same chemical ingredients all life on earth is made of.

The chemical nature of the material allows OLEDs to be built as sheet-like surface emitters compared to an LED where the light comes concentrated out of a tiny chip. Due to the characteristics of the materials it is therefore possible to manufacture thin, flexible surface light emitters with a remarkably uniform light distribution – an OLED panel.

The basic construction uses a quite complex layer structure with 15 or more layers to generate light at maximum efficiency. Individual layers can be manufactured as thin as 50nm and the active, light generating part of the layer stack comprises only a fraction of the overall thickness of the OELD panel.