Thickness effect on Schottky diode characteristics of ZnO thin film

Surface morphologies of the ZnO thin films with various thicknesses have been investigated. ZnO sol was prepared with zinc acetate dihydrate, 2-methoxyethanol, and monoethanolamine. Thicknesses of the ZnO films were controlled by a multiple coating process. The ZnO thin films were annealed at 750 degrees C. The film thickness increased as the coating time increased. From the XRD study, it is observed that the ZnO films exhibit wurtzite structure ( 002) and the diffraction intensity increased as the thickness increased. Effect of thickness on Schottky behavior was evaluated by measuring current-voltage characteristics. The pristine ZnO thin films with thickness of 132 nm exhibited Schottky diode characteristics with high rectification ratio.