Recovery of silver metallization from damaged silicon cells

Metallization is one of the key process steps to fabricate solar cells with high performance in a cost-effective way. Majority of photovoltaic solar cell manufacturing uses thick film screen print metallization with Ag containing paste to produce solar cells. The average lifetime of PV modules can be expected to be more than 25 years. The disposal of PV systems will become a problem in view of the continually increasing production of PV modules. These can be recycled for about the same cost as their disposal. The proposed method of acidic and basic etching of contacts, presented in this article can be successfully applied to broken solar cells from the landfill without a specialist analysis procedure. The amount of silver that can be recovered from the etching solution is up to 1.6 kg/t of broken solar cells. The step-by-step procedure improves efficiency of silver recovery. The best and easiest method for general verification of the silver etching rate is classic titration with suitable concentrations of titrant solution.