In-spite of intense research in the growth of ZnO over the years, the direct crystallization of ZnO on a metal coated/electrically conducting substrate by a solution growth process has not been carried out. We report one pot, low temperature (≤100 °C) and rapid growth (5 min) of ZnO nanorods over an electrically conducting substrate by using microwave irradiation assisted thin film deposition in a liquid medium without the use of any seed layer. High density (2 × 109/cm2), c-axis oriented, uniform and continuous ZnO nanorod films are grown over Cr/Si [chromium coated Si(1 0 0)] and ITO/glass (indium tin oxide coated glass) substrates whereas aluminium (Al) and gold (Au) coated Si yield non uniform film with mixed texture. Microwave irradiation for 5 min ensures strongly oriented growth of ZnO over Cr/Si and ITO/glass and mixed texture for semiconducting substrates (Si/Ge). The initial nucleation of ZnO nanorods may be due to the formation of thin amorphous oxide (Cr2O3) layer over Cr film, which subsequently changes to hydroxides (CrOH2, CrOH3) in contact with water.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering