10 - Biopolymer Composites in Light Emitting Diodes

Abstract

Polymers have been conventionally used as insulators and metal cables are coated in plastic to insulate them. However, after the discovery of the conductivity of polyacetylene, it significantly improved the doping process of conducting polymers. Biopolymer nanocomposites are the new class of functional nanomaterials that show the improved optical, thermal, and mechanical properties due to the synergistic effects resulting from the physical and chemical interactions. Biopolymers are made of living organism in a repetitive building of monomers which are covalently bonded to form larger structures. These nanocomposites offer the advantages of flexibility, light weight, low cost, and high impact resistance. Over recent years, significant attention has been received regarding the use of biopolymer in various research for their potential applications in electronic devices, laser, materials processing, food system, biomaterials processing, and biomedical application. These materials have been applied in electroluminescent devices, such as light emitting diodes (LEDs), optically pumped laser and display applications, and so on. Especially, in the LEDs is promising candidate for flat-panel display due to radiative recombination of singlet excitation and balance charge (electron and hole) injection in the active device region. Recently, new lighting device, such as LED and organic light emitting diode (OLED) are becoming popular day by day. Lighting is considered as a very common and well-known thing among the human life but technologies behind are undeniably implicit. This review covers broadly LEDs functions, types of different LEDs, application of biopolymer-composite in LEDs and OLEDs as well as briefly organic polymers used in LEDs. The main emphasize of review focuses on important aspects of LEDs application of biopolymers consisting biocompatible nanoparticles. The influence of the biocomposite on external quantum efficiency of LEDs and efficiency of the recombination process of charge injection will be facilitated which eventually lead the performance of LEDs.