Cyclic Utilization of Lead in Carbon-Based Perovskite Solar Cells

An environmentally friendly dissolving–precipitating method is developed to recycle lead from carbon-based perovskite solar cells (PSCs). N,N-Dimethylformamide (DMF) was used to dissolve PSCs and to obtain lead containing lixivium. NH3·H2O was used as a precipitator to extract lead ions from the lixivium. The result analyzed by inductively coupled plasma optical emission (ICP-OES) shows that 99.9% of lead can be extracted by NH3·H2O. Then, HI was used to generate PbI2. ICP-OES analysis and thermodynamic calculation are used to analyze the lead content. The results show that little PbI2 transforms into PbI42– due to the low concentration of hydroiodic acid (HI). The calculated lead recovery rate is 95.7%. The recycled PbI2 was used to fabricate carbon-based PSCs achieving an efficiency of 11.36%, which is comparable to that (12.17%) of carbon-based PSCs fabricated with commercial PbI2. The developed process provides a new approach for the cyclic utilization of lead in carbon-based PSCs to avoid lead pollution.