Effect of annealing on ZnO nanowires grown at low temperature

Our research demonstrates that thermal and pulsed laser annealing improve the structural and optical properties of ZnO nanowire films grown electrochemically from aqueous electrolytes at a temperature below 90°C. The structural and optical properties of the grown ZnO nanowires were characterized by transmission electron microscopy and by their photo- and electroluminescence. Our results indicate that the as-grown nanowire structures have considerable internal lattice strain. However, moderate thermal annealing and laser annealing induce strain relaxation, considerably improving optical and electrical properties, and thereby allowing the fabrication of devices, such as solar cells and light emitting diodes.