Microstructures and photoluminescence properties of three-dimensional multi-layered ZnO flowers by surfactant-free hydrothermal method

Three-dimensional multi-layered ZnO flowers were fabricated on Zn foils by surfactant-free hydrothermal method. Using urea mediated solution, the quantities and sizes of ZnO petals can be turned by the urea concentration. The growth mechanism of etching-deposition was proposed. Room temperature photoluminescence spectra of hierarchical ZnO were studied.