Fractal dimension and photoluminescence of ZnO tetrapod nanowhiskers

ZnO tetrapod nanowhiskers were prepared and characterized using fractal dimension analysis. The fractal dimension of well-developed ZnO nanowhiskers was higher than 1.7, while that of ZnO nanoparticles was lower than 1.6. In addition to UV band-edge emission, nanowhiskers of large fractal dimension having well-developed ZnO crystalline feet and a Zn phase at the tetrapod center exhibited two visible emissions at wavelengths of 419 and 438 nm at room temperature.