Chemists measure copper levels in zinc oxide nanowires

ZnO nanowires to grow out of the circular copper substrate in all directions, as seen in this scanning electron micrograph. Detail image shows copper droplets at the tip of some... Click here for more information.

Chemists at the National Institute of Standards and Technology (NIST) have been the first to measure significant amounts of copper incorporated into zinc oxide (ZnO) nanowires during fabrication. The issue is important because copper plays a significant—but not well-understood—role in important optical and electrical properties of the nanowires. Previous experiments found only trace amounts of copper.

Although zinc oxide is best known as a strong sunblock, cold remedy, itch reliever and paint pigment, nanotech engineers like it for its photoluminescence (the ability to emit light after absorbing electromagnetic radiation), field emission (the basis for advanced, high-definition flat-panel displays) and piezoelectric properties (stressing or changing shape when electricity is applied and producing electricity when stressed). ZnO nanomaterials may one day be used to improve solar cells, lasers, sensors, ultraviolet light sources, field emission sources and piezoelectric devices.