THE annoying flicker of fluorescent lights could be replaced by the cool white glow of zinc oxide LEDs, now that a US company has found a cheap way to crystallise the oxide from a solution.
White light-emitting diodes are usually made from crystals of the semiconductor gallium nitride grown on a sapphire base. But these crystals often develop flaws as they grow, and many end up unusable. The manufacturing process is so inefficient that the LEDs that do work are far too expensive for lighting homes or offices.
However, it is possible to use pure zinc oxide semiconductor crystals instead…
