This Small Business Innovation Research (SBIR) Phase I project addresses environmental concerns facing the cadmium telluride (CdTe) device industry. CdTe is widely used in infrared detectors and more recently in photovoltaic (PV) devices, which are anticipated to provide a significant portion of the world's electric power. As the PV device industry expands, it is confronted with rising waste-disposal costs and increasingly stringent environmental regulations. Thin-film PV modules contain less than 0.1% of metals relative to large bulk wastestreams, for which conventional recycling methods are impractical and wasteful. However, the minute quantities of Cd classify the modules as hazardous waste. Their disposal costs can run into the $400-$1000/ton range. This project will explore an innovative closed-loop, electro-chemical approach to recycle CdTe/CdS devices. Phase I will identify process parameters to remove, separate and retrieve the semiconductor layers. The data will be used to design a compact recycling capability that maximizes efficiency, minimizes processing steps, and avoids waste storage and transport. This closed-loop recycling technology primarily targets the CdTe thin-film photovoltaic industry. It offers a timely and expedient solution to manage manufacturing waste and module disposal. Its implementation could save over 80% on disposal costs and mitigate the economic burden of environmental compliance. It also has potential applications for recycling semiconductor devices in the infrared, sensor, and flat-panel display industries.
