Synthesis, characterization, and electrical conductivity of ZnO with different morphologies

ZnO samples with different morphologies were prepared using a simple direct precipitation method with Zn (NO3)2⋅ 6H2O and NH3⋅ H2O as raw materials. The morphology and purity of the ZnO powders were studied via scanning electron microscopy, energy dispersive X-ray spectrometry, and X-ray diffraction. Factors influencing the morphology of ZnO, such as NH3⋅ H2O concentration and aging temperature, were studied. Photoluminescence spectra and Raman spectra were also used to analyze the native crystal defects of the ZnO samples. The results showed that the ZnO samples prepared in this work possessed a hexagonal wurtzite structure with high purity. In addition, NH3⋅ H2O concentration and aging temperature were essential in controlling the morphologies of ZnO. The electrical conductivities of ZnO with different morphologies were different, which mainly depends on the different native crystal defects of the ZnO samples.