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 center dot 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 center dot 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 [PbI4](2-) 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.