ZnO tetrapod nanocrystals

ZnO has received considerable attention because of its unique optical, piezoelectric, and magnetic properties. It also readily self-assembles into a family of nanocrystalline structures. We review the current status of research into ZnO tetrapod nanocrystals. These crystals consist of a ZnO core in the zinc blende structure from which four ZnO arms in the wurtzite structure radiate. The arms are cylinders of hexagonal cross section, with each arm of equal length and diameter. Possible applications in optoelectronics, photovoltaics, spintronics, and piezoelectricity are discussed.