Connected AZO Nanorods for Sensitivity Enhancement of Chemical Sensors at Room Temperature
In this work, the vertically aligned, high conductive Al-doped ZnO nanorod thin film was prepared by multi-layers grown method in solution process .This method of connected nanorod structure is unique of its kind compared with existing hydrothermal process for preparing nanorod. The diameter of AZO nanorod is around 14~16nm with [002] preferred orientation. The Hall measurement indicates the AZO nanorod exhibits high layer conductivity of 280 S/cm. The XPS characterization indicates that the AZO nanorod annealed in forming gas contain high percentage of non-binding oxygens that is suitable for sensor application. The sensing performances of the synthesized nanorod thin film towards the detection of oxidizing agents were analyzed by the current (I)–voltage (V) characteristics in room temperature. With high surface area, the AZO shows sensitivity of 72%, 1660%, and 4.34 x106 % for H2O2, ethanolamine and acetic acid, respectively. 1.02 μM (S/N=3) is the detection limit with broad range of 0.015mM to 29mM is demonstrated for sensing H2O2.