Physicists from the University of Southampton have "convincingly demonstrated" the first steps in science that might one day improve LEDs and solar cells.
Related to photonic crystals, in which light is refracted by regular arrays of tiny structures, 'Anderson localisation' causes predictable behaviour in waves passing through random arrangements of tiny structures.
In particular, light would become trapped in materials exhibiting photonic Anderson localisation, travelling in complex looping paths known as 'modes'.
Source:
http://www.electronicsweekly.com/Articles/2013/04/08/55897/old-science-might-make-better-leds-and-solar-cells.htm