Researchers in Germany have grown ordered, vertically aligned zinc oxide nanorods that emit laser light. The laser excitation down to a spot size smaller than 1µm and found that single nanorods standing on a substrate could lase. The nanorod arrays could be used to make UV nanolaser devices and light-source displays.

Zinc oxide (ZnO) is a wide bandgap semiconductor that emits laser light in the ultraviolet range up to room temperature. ZnO nanorods could be used as building blocks for nanolasers. However, it is difficult to produce well-ordered, uniformly sized and aligned arrays of 1D ZnO nanostructures that are needed for practical applications.

To make nanolaser devices, ZnO nanorod-based pn junctions are needed. Such electrically driven ZnO nanolasers could serve as highly efficient miniaturized light sources.