Zinc oxide nanowire lasers boost DVD storage capacity

Ultraviolet semiconductor diode lasers are widely used in data processing, information storage and biology but their applications are said to have been limited by size, cost and power.

The current generation of ultraviolet lasers is based on gallium nitride, but Jianlin Liu, a professor of electrical engineering, and his colleagues have made a breakthrough in zinc oxide nanowire waveguide lasers, which can offer smaller sizes, lower costs, higher powers and shorter wavelengths.

Until now, zinc oxide nanowires could not be used in real-world light-emission applications because of the lack of p-type material needed by all semiconductors. Liu is said to have solved this problem by doping the zinc oxide nanowires with antimony — a metalloid element — to create the p-type material.

The p-type zinc oxide nanowires were connected with n-type zinc oxide material to form a p-n junction diode. Powered by a battery, highly directional laser light emits only from the ends of the nanowires.