Exeter University researchers have found that the nanoscale structure of the wings of the African Princeps nireus butterflies closely matches the most advanced photonic materials under development in laboratories around the world.

Its fluorescent blue patches are formed from two-dimensional photonic crystal positioned above distributed Bragg reflectors. Fluorescent pigment in the photonic crystal structure of the butterfly wing absorbs light from blue skies and emits darker blue light.

The photonic crystal-distributed Bragg reflector combination concentrates light and directs it outward. Such light-emitting diodes would be much more efficient than today’s models, which scatter light in all directions, causing much of the light they produce to be reabsorbed by the devices’ material.