Relationship between Carrier Density and Precursor Solution Stirring for Lead-Free Tin Halide Perovskite Solar Cells Performance

The oxidation of tin halide perovskite precursor (THP) with the solvent dimethyl sulfoxide (DMSO) has intriguing drawbacks. We found that THP oxidation under progressive stirring can be hindered by the addition of GeI2. Subsequently, the stirring time of the precursor solution affects the carrier density and semiconducting properties of fabricated films, because DMSO can increase the oxidation induced carrier density. On the other hand, dimethylformamide (DMF) can suppress the oxidation induced carrier density. After 24 h, an efficiency of 10.26% is found when DMF is used and 7.12% is found when DMSO is used as a stirring solvent.

Automated summary

The oxidation process of tin halide perovskite precursor (THP) with dimethyl sulfoxide (DMSO) as the solvent has interesting drawbacks. Adding GeI2 can hinder THP oxidation under progressive stirring. The stirring time of the precursor solution affects the carrier density and semiconducting properties of the fabricated films, as DMSO increases the oxidation-induced carrier density. On the other hand, dimethylformamide (DMF) suppresses the oxidation-induced carrier density. After 24 hours, an efficiency of 10.26% is achieved with DMF as the stirring solvent, while 7.12% is achieved with DMSO.