An OLED or light emitting diode, based on the phenomenon of electro phosphorescence, emits light when voltage passes through it. It consists of organic material that has limitless combinations, varying in its color and durability. Though, Its practical application in mobile phone displays has begun already, it is being touted as the favorite to succeed incandescent and fluorescent lighting.
Flourescent tubes have been on the favorite list in comparison to OLEDs because of its higher efficiency of about 50 to 70 lumen per watt. Paving a way out, Novaled and the Institute of Applied Photosynthesis of the Dresden technical university have come up with OLEDs with higher efficiency mark of 90 lumen per watt. In fact, with the help of special 3D out coupling measures, they have achieved 124 lm/W.
OLED is composed of an emissive layer, a conductive layer, a substrate, and anode and cathode terminals. Emissive layer is sandwiched between two transport layers that’s connected to cathode and anode respectively. On application of voltage, the holes and electrons are generated from each of the electrode having positive and negative electric charge respectively. Transport layer carries the electric charge from the respective electrodes to the emissive layer, where organic material transforms emissive layer into an excitation state. The light is emitted when the layer returns to its original stability.
• These large area-emitting devices are flexible, transparent and color-tunable, thus enabling manufacturing of varied new OLED lamp designs.
• OLEDs are not only a source of quality white light, but they are also environment friendly as they do not contain any unwanted metals such as mercury, which is present in efficient CFL lamps.
• It has an upper hand in comparison to LCDs as it offers greater range of colors, brightness and viewing angle.
When we consider the efficiency and wide range of applicability, OLEDs are really the future lighting source. At the same time, OLEDs offer the potential to become even more efficient than energy-saving bulbs.