Electrical engineers have enlisted the help of the humble jellyfish in their efforts to develop better light-emitting diodes (LEDs) , according to a report published in the December 1 issue of the journal Advanced Materials. The Pacific Ocean jellyfish Aequorea victoria, it appears, produces just the kind of light that researchers try to coax from such crystalline semiconductors as gallium arsenide or indium phosphide. Moreover, the jellyfish accomplishes this with great efficiency: its light comes from a substance dubbed green fluorescent protein (GFP), which collects the energy produced in a certain cellular chemical reaction and emits it as green light from a molecular package known as a chromophore.
Inspired by Aequorea’s green glow, Mark Thompson of the University of Southern California and his colleagues synthesized chromophore-like molecules, which they then seeded onto a matrix of organic molecules in an organic LED (OLED). The chromophore-like molecules, they reasoned, would function as "dopants," converting energy captured from the matrix into light. After tweaking the molecular structures, the team produced both green and orange OLEDs.
Researchers are keen to develop such OLEDs for flat-screen, portable computer displays because they would be simpler and cheaper to make than their nonorganic counterparts. Although not so efficient as existing devices, the chromophore-based model should improve with further work. "There are an enormous variety of fluorescent organisms," the team notes. "Other materials can be prepared using the insight provided by naturally occurring systems, which may be useful in electronic and optoelectronic applications."
