The influence of different seeds solution concentration upon chemical bath deposition process on the morphology of ZnO nanorods

The unique characteristics of zinc oxide (ZnO) nanorods including high surface to volume ratio and fast electron transfer makes this material potentially applicable for various areas such as photovoltaic devices, dye-solar cells, electric field, and biomedical. In this work, the influence of different seed solution concentration on the morphology of ZnO nanorods using chemical bath deposition (CBD) method was investigated. The seed solutions with 3 different concentration of 0.005, 0.025 and 0.05 M were prepared by dissolving 1: 1 equimolar zinc nitrate tetrahydrate (Zn (NO ₃ ) ₂ .4H ₂ O, Merck) and hexamethylene tetraamine (C ₆ H ₁₂ N ₄ / HMTA, Merck) in water at 0°C for 1 hour. The formation of seed layers was carried-out by spin coating of the precursors on the glass substrate, followed with annealing at 200°C for 5 minutes. Further growth of ZnO nanorods was performed by CBD at 90°C for 3 hours. The morphology of ZnO nanorods was characterized by using field emission scanning electron microscopy (FESEM). The results showed that seeds concentration of 0.005 M formed inhomogeneous nanorods with average diameter of 161 nanometers, meanwhile 0.025 and 0.05 M has successfully formed more homogeneous nanostructures with average diameter of 205 and 427 nm, respectively. On the basis of investigation, it has been confirmed that higher concentration of seed solution provided more suitable formation of ZnO nanorods.