The transition to renewable energy is critical for decarbonizing global energy systems. Solar panels, alongside wind turbines, play a pivotal role in achieving this transformation. With projected annual photovoltaic production surpassing 1 terawatt peak (TWP) in 2025, the deployment of tens of billions of solar panels is essential to meet energy goals. However, as these panels reach the end of their lifecycle, the challenge of sustainable disposal or recycling arises. Opting for circular recycling over landfilling offers numerous benefits, including the recovery and reuse of valuable materials, which are vital to maintaining production sustainability. This underscores the urgent need for a circular photovoltaic market where production and recycling capacities are aligned.

Lead perovskite solar cells, a next-generation photovoltaic technology, have entered the field as a promising new technology with their high efficiency, scalability, and unique material properties, such as tunable bandgaps and high absorption coefficients. Perovskite solar cells hold both promises and new challenges with respect to recycling and sustainability of photovoltaic technologies. On the one hand, perovskite solar cells can be deposited from solutions, enabling material recovery with very high selectivity. On the other hand, perovskites pose environmental challenges, particularly regarding the sourcing and recycling of lead halides. Addressing this, our research focuses on i) developing circular recovery and recycling processes for all materials used in a perovskite solar cell and ii) integrating perovskite solar cells into a circular economy by repurposing lead waste into materials for new solar cell fabrication.

With respect to circular recycling of perovskite solar cells, we demonstrated a closed-loop recycling of MAPbI3 perovskite solar cells that achieved a 99.97% mass recovery through a layer-by-layer solvent extraction method. Critical components, including ITO glass, SnO2, MAPbI3, and spiro-OMeTAD, were recovered and purified. Devices fabricated with recycled materials maintained performance on par with those using virgin components, with peak efficiencies reaching 19%. A techno-economic analysis showed that implementing this recycling approach could reduce material costs by 63.7% in lab-scale production. These results underscore the potential of closed-loop recycling to enhance the sustainability and cost-effectiveness of perovskite photovoltaic technology​.

With respect to utilizing lead, we developed a recycling process starts to convert contaminated lead into lead iodide (PbI₂). This method achieves near-complete conversion, with a Faradaic efficiency close to 1. An essential step involves purifying the synthesized PbI₂ through single-crystal growth, yielding, in one example, 35% pure PbI₂, while the remaining material is recycled for subsequent loops. This scalable process produces PbI₂ at approximately 1g per hour, with potential for industrial application by increasing electrode area.The recovered PbI₂ is directly utilized to fabricate new perovskite solar cells, achieving efficiencies exceeding 20%. This result not only demonstrates the viability of recycling perovskite materials but also establishes a sustainable pathway for addressing the environmental concerns of lead waste. By converting contaminated lead from various sources, including legacy lead waste from industries and household applications, our approach eliminates significant ecological hazards and contributes to a circular economy.