We have successfully synthesized self-organized radialized flower-like ZnO micron-crystals by employing Zn(NO3)2·6H2O, NH3·H2O as the starting materials without surfactants, template supporting and structure-directing solvent at a low temperature (60 °C). Characterizations were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and room temperature photoluminescence (PL) measurements. A possible growth mechanism, the influence of pH value on the formation of crystalline ZnO and the photolu...