Towards efficient near-infrared fluorescent organic light-emitting diodes

Light-emitting diodes: Near-infrared fluorescence from organic molecules Organic (carbon-based) light-emitting diodes (LEDs) that emit near-infrared light can be built by linking together large organic molecules called porphyrins, offering many potential industrial and medical applications. Organic near-infrared LEDs have several advantages over conventional LEDs based on inorganic semiconductors, including mechanical flexibility, biocompatibility and the absence of polluting heavy metals. Researchers in the UK and Italy led by Harry Anderson at the University of Oxford and Franco Cacialli at University College London explored the potential of linked porphyrin structures that fluoresce at near-infrared wavelengths. The optical properties of the materials are improved by engineering the molecular structure and a quantitative model is presented to explain the efficient emission. This research provides understanding of exciton dynamics and points towards innovative uses of near-infrared light in applications including light therapy, optical communications, biosensors and biometric systems.