Controlling the morphology of ZnO structures via low temperature hydrothermal method and their optoelectronic application

Here, zinc oxide (ZnO) with various morphologies were synthesized via a simple hydrothermal method at low temperature of 70 ℃. Field emission scanning electron microscopy (FESEM) characterization exhibited that the block and flower-like samples could controllable grow on graphite and graphene substrate, respectively. In comparison, rod-like sample was fabricated in the absence of substrate. X-ray diffraction (XRD) indicated that the rod and flower-like samples were the well-crystallized wurtzite ZnO structure, and the block-like sample was a hybrid of ZnO and Zn(OH)2. Graphite and graphene substrate were the reason that affects the formation of block hybrid of ZnO and Zn(OH)2 crystal and flower-like ZnO, respectively. The results indicated that the substrate plays a crucial role in synthesizing ZnO sample with various morphologies and types. Additionally, the property characterization demonstrated that the flower-like ZnO exhibited the best optoelectronic performance compared with the other two structures.