Annealing effect on the morphologies and photoluminescence properties of ZnO nanocombs

In order to examine the annealing effect on morphologies and photoluminescence properties of the as-synthesized ZnO nanocombs, they were annealed in argon and in air at 800 °C for 10 h, respectively. The SEM, TEM, HRTEM, and PL examination results show that the morphologies and photoluminescence properties of ZnO nanocombs annealed in argon are quite different from those of ZnO nanocombs annealed in air. To anneal ZnO nanocombs in air caused the disappearance of combs, the enhancement of ultraviolet emissions, and the disappearance of emissions in the visible spectral region. On the other hand, the combs still existed, and the green emission centering at 500 nm still existed after annealing ZnO nanocombs in argon. The mechanisms for the morphological and photoluminescence evolution of annealed ZnO nanocombs are also proposed.