Sustainable KCl-Assisted PbI₂ Recycling for High-Performance Quantum Dot Solar Cells

Area of Science:

• Materials Science
• Chemical Engineering
• Renewable Energy

Background:

• Lead-based semiconductors are vital for advanced optoelectronics.
• Recycling lead waste offers a scalable and cost-effective fabrication route.
• Achieving device-grade semiconductor quality from recycled lead remains a challenge.

Purpose of the Study:

• To develop an additive-assisted lead recycling strategy for producing high-purity semiconductor precursors.
• To address challenges in synthesizing high-quality lead sulfide (PbS) and cesium lead iodide (CsPbI3) quantum dots (QDs).
• To demonstrate the effectiveness of this strategy in improving optoelectronic device performance.

Main Methods:

• Introduction of trace potassium chloride (KCl) during the lead recycling process.
• Utilizing KCl to enhance PbI2 crystallization and impurity removal.
• Investigating the impact of residual KCl on PbS and CsPbI3 QD properties and device performance.

Main Results:

• Additive-assisted recycling yielded high-purity PbI2, enabling superior PbS QD solar cells (13.3% efficiency).
• CsPbI3 QD solar cells fabricated using this method achieved 16.6% efficiency, outperforming commercial precursors.
• The KCl additive improved QD colloidal stability, photophysical properties, surface integrity, and carrier lifetimes.

Conclusions:

• The additive-assisted metallurgy-semiconductor coupling strategy provides an energy-efficient pathway to high-purity semiconductor precursors from lead waste.
• This sustainable approach enhances the performance of lead-based quantum dot optoelectronic devices.
• The method demonstrates universality across different lead-based QD systems, paving the way for advanced applications.