Electrochemical properties of Ag-doped ZnO nanorods synthesized by chemical bath deposition method.

Ag-doped ZnO nanorods from 5% to 20% were synthesized on a seeded substrate using chemical bath deposition (CBD) method. Structural properties were studied by Scanning Electron Microscopy (SEM), and X-ray Diffraction Spectroscopy (XRD). SEM images showed that the diameter of nanorods increased from 68 nm to 87 nm. EDX and XRD confirmed the presence of Ag in ZnO crystal lattice. Optical properties were studied using Photoluminescence (PL) and UV-Visible spectroscopy. Band gap of Ag-doped ZnO nanrods were calculated from optical measurements and found to decrease from 3.25 eV to 2.99 eV with increasing doping concentration. Electrical transport properties of nanorods were analyzed by impedance spectroscopy using the Cole-Cole plot technique and conductivity was measured using the Vander Pauw method. Impedance analysis showed that the resistance of Ag-ZnO nanorods decreased with increasing Ag doping from 5% to 20%. Electrical results indicated that the resistivity of Ag-ZnO decreased with increasing doping concentration. Electrochemical properties, such as conduction band and valence band of Ag-doped samples were extracted from Cyclic Voltammetry. The optimized Ag-ZnO electrodes based on electrochemical studies will be developed for dye-sensitized solar cells.