Effect of annealing of ZnO/Ag double seed layer on the electrical properties of ZnO/Ag/ZnO heterostructure nanorods

A simple hydrothermal method was used in order to grow ZnO nanorods on ZnO/Ag double seed layer. With annealing of the ZnO/Ag seed layer at different temperatures in the range of 150-450 degrees C, the effect of Ag embedded layer on the properties of ZnO nanorods was investigated. The ZnO/Ag seed layers and ZnO heterostructure nanorods were characterized by AFM, UV spectroscopy, FESEM and XRD to study the morphological and structural properties. The surface grains on ZnO/Ag seed layer considerably decreased at the higher annealing temperatures. With deposition ultrathin Ag layer on ZnO seed layer and increasing annealing temperature, the nanorods diameter increased. The XRD analysis confirmed that the (002) peak intensity increased in ZnO nanorods grown on ZnO/Ag seed layer annealed at lower temperatures and significantly decreased at the higher annealing temperatures. The ZnO heterostructure nanorods grown on ZnO/Ag seed layer annealed at 150 degrees C revealed the lowest electrical resistance. The UV photocurrent of nanorods sensor based on ZnO/Ag/ZnO nanorods is enhanced about 25% at the optimum annealing temperature 150 degrees C.