Excitonic prospects for UV

With the incandescent bulb beaten in terms of efficiency, and fluorescent lighting in its sights, wide bandgap semiconductors are looking for new territories to conquer. One direction to go is higher power and coherence, and blue-violet nitride-based laser diodes are now coming into commission in high-definition DVD (HD-DVD) and Blu-ray optical storage systems offering up to 25 gigabytes on a single layer. Another course is that towards shorter wavelengths – into the ultraviolet (UV).