The LED polymer (light-emitting diode) - sometimes called light-emitting polymer or polyLED - is a technology based on the use of polymer as a semiconductor material in LEDs. Polymers are chemicals that consist of large molecules that themselves are made up of many smaller, simpler molecules: proteins and DNA are examples of naturally occurring polymers; many others, such as nylon, are artificially created. Because of their flexibility and strength, polymers are used for products such as car bumper and bulletproof vests.
Because the polymers are light and flexible, they can be used simply and inexpensively for the creation of thin film screens for future technologies such as the electronic journal. Polymer LEDs have a number of inherent qualities that are ideal for these applications: they allow full-spectrum color displays, high brightness at low drive voltages, reflection-free display and long service life. It is now possible to create a small text display by structuring the polymer material and the electrodes. The technology also holds great promise as the basis for cheaper and simpler lighting sources.
LEPs have been identified as a promising class of materials for organoelectric applications. The easy processing and greater mechanical flexibility of the LEPs allow LED polymers to become less expensive and on large sheets making them suitable for large screens. LEPs also offer a lot of promise as a cheaper and simpler lighting source because of its lower power consumption. However, the use of PLED in a wide range of consumer applications in a cost-effective manner is limited by the short lifespan and the decrease in efficiency resulting from spatial loading effects. This has motivated the polymeric chemists to create new types of LEP with properties adapted by incorporation of lateral groups or by copolymerization. This paper aims to review the use of light emitting polymer (LEPs) as electroluminescent polymer LED materials and to summarize the contributions made by various chemical groups to improve the efficiency of PLEDs.