Catalyst-free growth of green-emitting arrayed ZnO nanorods at low temperature

Green-emitting arrayed ZnO nanorods were fabricated on the ZnO nanoparticulate film by simply re-firing the film in the mixture of nitrogen and hydrogen. To generate the arrayed nanorods, the annealing temperature in the air should be above 450 °C, the flow rate of the hydrogen should be higher than 10 mL/min, the re-firing temperature must be controlled in the range from 450 to 550 °C, and the hydrogen should be continually supplied in the process of cooling.