Firefly-inspired LED shines brighter

An organic light-emitting diode that mimics the three-layered structure of a firefly’s lantern shines brighter than conventional OLEDs, a development that could lead to TV and computer screens that use less energy (Nano Lett. 2016, DOI: 10.1021/acs.nanolett.5b05183). The lantern of the firefly species Pyrocoelia rufa is covered in chitin structures 10 µm wide that lie like roofing tiles, with nanoscale ridges decorating their surfaces. These structures better match the index of refraction of air than plain chitin, and they reduce internal reflection, which improves light transmission out of the lantern. Below the chitin lies a layer of light-producing tissue, and below that is a light-reflective layer that bounces light out of the lantern. Ki-Hun Jeong of the Korea Advanced Institute of Science & Technology and colleagues mimicked these layers in their design: The top layer is a polymer resin patterned with chitin-like structures, followed by a layer of standard green OLED material and then an aluminum reflector. The bioinspired OLED shines about 60% brighter than a conventional green OLED, Jeong says.