Organic Light Emitting Diodes (OLEDs) emerged 30 years ago as a very
promising flat-panel display technology because of their lots of advantages. OLEDs
consist of several nanometer-scale thin films between anode and cathode, which can be
integrated on various substrates, especially the ultra-thin and flexible substrates. As a
result, OLEDs present advantages of high efficiency, lightweight, fast response time,
wide viewing angle, vivid color, high contrast and etc. After development of
technology improvement over past several decades, enormous progress has been made
to promote OLED products to be launched into market. In this chapter, we review the
development history of OLEDs, with special emphasis on several key technical
innovations which significantly advanced the industrialization. From two main
application filed of display and lighting, we describe the working mechanism, technical
development, advantages and disadvantages, and production status of OLED
technology.
Keywords: Composite cathode layer, Display, Electrical doping,
Electroluminescence (EL), Emitter doping, Flexible OLED, ITO surface
treatment, Light outcoupling, Lighting, Multilayer structure, Organic lightemitting
diode (OLED), Phosphorescent emitter, Thermally activated delayed
fluorescence.