Understanding metallic and ionic contamination in photovoltaic wet chemistries from chemical delivery systems

As photovoltaic cell manufacturers strive to improve yield and cell efficiency it is increasingly important to carefully select the materials of construction used in chemical delivery systems. Low purity materials of construction are prone not only to chemical degradation but they also contribute metallic and ionic contaminates into critical high purity process chemistries. This metallic and ionic contamination study analyzed several materials commonly used as wetted surfaces in photovoltaic chemical delivery systems. Contaminants leached from each material were monitored as a function of time and temperature. Results clearly demonstrate the wide range of contamination contribution into process chemistries from the different materials. The data can be used by engineers to reduce the introduction of metallic and ionic contaminants into their critical process chemistries by carefully selecting the materials of construction used in their chemical delivery system.