Efficient yet inexpensive light-emitting diodes made of zinc oxide could one day replace today's state-of-the-art gallium nitride-based devices. Key to the discovery is production of positively charged carriers p-type doping in zinc oxide using rapid pulse thermal processing. "LEDs require both p-type, positively charged carriers, and n-type, negatively charged carriers, materials in close contact," said Jun Xu, lead author of the paper published recently in Applied Physics Letters (Vol. 92, Issue 16). "Zinc oxide is potentially a good light emitter because of its high exciton binding energy and vertically aligned nanostructure." The new technique overcomes problems encountered with other techniques and provides the ability to generate positive carriers in zinc oxide. This opens possibilities for developing reliable efficient LEDs and other applications such as advanced electronics operated in hostile environments, photo sensors, photovoltaic devices and radiation detectors. Funding was provided by the Laboratory Directed Research and Development program.