Effects of synthesizing parameters on surface roughness and contact angles of ZnO nanowire films

Effects of the synthesizing parameters on the surface roughness and the contact angles of ZnO nanowire films were studied in this paper. ZnO nanowire films were synthesized with the hydrothermal method on glass substrates, and the synthesizing parameters include the concentrations of the growth solution and the seed layer solution, the growth time span as well as the temperature. Atomic force microscopy and scanning electron microscopy were employed respectively to characterize the surface and the profile roughness of ZnO nanowire films. The measurement results by atomic force microscopy were in agreement with that by scanning electron microscopy, hence the former was used for the investigation of aforementioned effects. Relationships between the synthesizing parameters, the surface roughness and the contact angles of ZnO nanowire films were established, revealing that the synthesizing parameters affected significantly not only the surface roughness but also the contact angles of ZnO nanowire films. The results can be used for batch fabrication of ZnO nanowire-based structures and these structures-based sensors in a wide variety of applications.