SBIR-STTR Award

An important problem in the field of photovoltaic (PV)technology is that there is currently no effective process toremove and recycle the semiconductor materials in anenvironmentally benign fashion. The metals which can be presentin thin film PV devices may include cadmium, copper, gallium,indium, selenium, and tellurium. They must be separated from areglass, plastic, or similar low cost substrates.Hydrometallurgical solvent systems have been developed which havebeen demonstrated to be very effective in solubilizing metals.This solvent will be highly effective in leaching thesemiconductor metals in PV wastes from their substrates. Theadvantages of this process include the thoroughness of the metalsdissolution and the proven ability to achieve 100% reclamationand recycling of the solvent. The recovered metals will besuitable for sale to metal refiners. Other than well-cleanedglass or similar substrate exiting from the process, there willbe no solid, liquid, or gaseous waste streams. If there is anyresidual leaching solvent on the exiting substrates, it can beeasily and quantitatively removed, collected, and reused bydrying. The resulting substrate will be free of metals and willbe suitable for conventional recycling. Phase I will demonstrate:(1) the process on the laboratory bench using representativesamples of PV materials, (2) that the substrate material leavingthe process is free of contaminants and satisfies EnvironmentalProtection Agency Toxicity Characteristic Leaching Procedures,and (3) that mixed metal oxides can be produced with 100% recycleof the solvent for the entire process. The suitability forrecycling of the metal oxides to PV module manufacturers, or forselling them to established metallurgical refineries, will beevaluated. Anticipated Results/Potential Commercial Applications as described by the awarded:The goal is to develop a commercializedtechnology to recycle or reclaim PV semiconductor waste. Acentralized processing facility will be established which willprofitably reprocess PV manufacturing waste and spent PV cellsinto metal oxide chemicals either for sale or for reuse by PVcell manufacturers.

An important problem in the field of photovoltaic (PV)technology is that there is currently no effective process toremove and recycle the semiconductor materials in anenvironmentally benign fashion. The metals which can be presentin thin film PV devices may include cadmium, copper, gallium,indium, selenium, and tellurium. They must be separated from areglass, plastic, or similar low cost substrates.Hydrometallurgical solvent systems have been developed which havebeen demonstrated to be very effective in solubilizing metals.This solvent will be highly effective in leaching thesemiconductor metals in PV wastes from their substrates. Theadvantages of this process include the thoroughness of the metalsdissolution and the proven ability to achieve 100% reclamationand recycling of the solvent. The recovered metals will besuitable for sale to metal refiners. Other than well-cleanedglass or similar substrate exiting from the process, there willbe no solid, liquid, or gaseous waste streams. If there is anyresidual leaching solvent on the exiting substrates, it can beeasily and quantitatively removed, collected, and reused bydrying. The resulting substrate will be free of metals and willbe suitable for conventional recycling. Phase I will demonstrate:(1) the process on the laboratory bench using representativesamples of PV materials, (2) that the substrate material leavingthe process is free of contaminants and satisfies EnvironmentalProtection Agency Toxicity Characteristic Leaching Procedures,and (3) that mixed metal oxides can be produced with 100% recycleof the solvent for the entire process. The suitability forrecycling of the metal oxides to PV module manufacturers, or forselling them to established metallurgical refineries, will beevaluated. Anticipated Results/Potential Commercial Applications as described by the awarded:The goal is to develop a commercializedtechnology to recycle or reclaim PV semiconductor waste. Acentralized processing facility will be established which willprofitably reprocess PV manufacturing waste and spent PV cellsinto metal oxide chemicals either for sale or for reuse by PVcell manufacturers.