Chemistry:Chemical bath deposition

Chemical bath deposition (CBD), or chemical solution deposition (CSD), is a method to deposit thin films and nanomaterials, first described in 1869. It can be employed for large-area batch processing or continuous deposition. In 1933 Bruckman deposited lead(II) sulfide (PbS) thin film by chemical bath deposition, or solution growth method. This technique is extensively used to deposit buffer layers in thin film photovoltaic cells.

Advantages and disadvantages

The major advantage of CBD is that it requires in its simplest form only solution containers and substrate mounting devices. One of the drawbacks of this method is the wastage of the solution after every deposition. Chemical bath deposition yields stable, adherent, uniform, and hard films with good reproducibility by a relatively simple process. The growth of thin films strongly depends on growth conditions, such as duration of deposition, composition, and temperature of the solution, and topographical and chemical nature of the substrate.

Reaction mechanism

The chemical bath deposition involves two steps, nucleation and particle growth, and is based on the formation of a solid phase from a solution. In the chemical bath deposition procedure, the substrate is immersed in a solution containing the precursors. This method depends upon parameters like bath temperature, pH of the solution, the molarity of concentration, and time. Chemical bath deposition does not cause physical damage in the substrate