Characteristics of annealed ZnO:Cu nanoparticles prepared by spray pyrolysis

The effect of the annealing temperature (T _a) on the thermoluminescence, surface morphology, electrical and structural properties of the ZnO:Cu nanoparticles obtained by the spray pyrolysis method at 500°C substrate temperature was studied. All the ZnO:Cu nanoparticles annealed in the range from 200 to 450 °C are polycrystalline with (002) preferential orientation. The resistivity decreases as T _a increases until it reaches a value of 0.07 Ohm cm for T _a = 350 °C. For higher temperatures the resistivity experiences a slight increase. The grain size also increases when T _a increases as observed in data calculated from X-ray measurements.