Growth and characterization of Cl-doped ZnO hexagonal nanodisks

Cl-doped ZnO nanodisks were grown on a Si(111) substrate using a thermal evaporation method. The prepared nanodisks exhibited a hexagonal shape with an average thickness of 50 nm and average diagonal of 270 nm. In addition, undoped ZnO disks with hexagonal shape were grown under the same conditions, but the sizes of these undoped ZnO disks were on the micrometer order. A possible mechanism was proposed for the growth of the Cl-doped ZnO nanodisks, and it was shown that the Cl1− anions play a crucial role in controlling the size. X-ray diffraction and Raman spectroscopy clearly showed an extension in the crystal lattice of ZnO because of the presence of chlorine. In addition, these nanodisks produced a strong photoluminescence emission peak in the ultraviolet (UV) region and a weak peak in the green region of the electromagnetic spectrum. Furthermore, the UV peak of the Cl-doped ZnO nanodisks was blueshifted with respect to that of the undoped ZnO disks.