Reproducible chemical bath deposition of ZnO by a one-step method: The importance of "Contaminants" in nucleation

A study was conducted to demonstrate the effect of contaminants to the chemical bath deposition (CBD) of ZnO without pre-deposited seed layer. The study found that ZnO film can be obtained on glass using contaminated impure-ethanolamine (impure-EA). The study used inductively coupled plasma (ICP) elemental analysis of EA to find the presence of 15 ppm Fe in the impure-EA. The study found that ZnO precipitation occurred for contaminated deposition, while less precipitation found with non-contaminated solutions. The study also found that the addition of metal salts to the deposition solution can form hydrated oxide colloids of FeOOH or MnOOH. The study revealed that the colloids of Fe and Mn oxide act as nucleation agents for ZnO growth. The study observed a visible difference in reflectivity between the bottom half of the substrate immersed in solution and the upper part.