Doping and defects in the formation of single-crystal ZnO nanodisks

High purity growth of polar surface dominated ZnO nanodisks was fabricated by introducing In ions in the raw material by thermal evaporation process without a catalyst. The nature of the sharp-contrast lines in the disks was investigated. The results suggested that the existence of sharp-contrast lines is due to the local segregation of In. Defects were initiated by segregation of the doping element of indium, which reduced the surface energy of ZnO (0001) leading to the fastest growth of the nanodisks along < 01 (1) over bar0 >. The preferred growth along < 01 (1) over bar0 > is considered to maximize the effect of the piezoelectricity. (c) 2006 American Institute of Physics.