The National Institute of Standards and Technology scientists said their achievement is important because copper plays a significant, but not well-understood, role in the optical and electrical properties of the nanowires.

Although zinc oxide is best known as a strong sunblocker, cold remedy, itch reliever and paint pigment, nanotech engineers like it for its photoluminescence -- the ability to emit light after absorbing electromagnetic radiation. The scientists said zinc oxide nanomaterials might one day be used to improve solar cells, lasers, sensors, ultraviolet light sources, field emission sources and piezoelectric devices.

The NIST chemists used a variety of measurement techniques to discover the zinc oxide wires contain a surprising amount of copper -- between 5 percent and 15 percent. High-resolution imaging studies of zinc oxide nanowires reveal the copper manages to fit into zinc oxide's regular crystalline structure without disrupting it.

The study is part of research designed to find the best methods of determining the concentration and distribution of atoms in nanostructures.

The findings are detailed in journal Nano.