Indium-doped ZnO nanorods grown on Si (1 1 1) using a hybrid ALD-solvothermal method

Atomic layer deposition (ALD) followed by microwave hydrothermal processing was successfully employed for producing doped and vertically aligned ZnO nanorod arrays with different aspect ratio. Firstly, a textured ZnO layer with preferential orientation normal to the c -axis was formed on substrate (1 1 1) silicon single crystals by means of the ALD technique. This was achieved through the decomposition of diethylzinc at 190 °C and 3.289  ×  10⁻⁴ atm, which provided an adequate template with nucleation sites, favoring further growth of vertical nanorods. Subsequently, nanorod array growth was produced on the same surfaces through solvothermal synthesis using as promoter a solution of Zn(NO₃)₂. In addition, growth of indium-doped ZnoO nanorods over the substrates was produced by using In(CH₃COO)₃ as a doping agent. The method presented allows good quality ZnO and Zn_1−x In_x O thin films to be obtained. Photoluminiscence spectra show clear evidence of the inclusion of indium in the ZnO matrix. The higher intensity ratio Zn_0.96In_0.4O/ZnO was increased 40-fold, demonstrating such an effect. (paper)