U.K. scientists appear to be on the right path to cheap production enlightenment. According to NewScientist:
One solution is to grow the LEDs on sapphire, which shrinks and cools at much the same rate as GaN. But the expense is too great to be commercially competitive.
Now Colin Humphreys's team at the University of Cambridge has discovered a simple solution to the shrinkage problem.
They included layers of aluminium gallium nitride in their LED design. These layers shrink at a much slower rate during cooling and help to counteract the fast-shrinkage of pure gallium nitride. These LEDs can be grown on silicon as so many other electronics components are. "They still work well as LEDs even with those extra layers inside," says Humphreys.