Researchers from Italy’s University of Florence have found that graphene could significantly improve the efficiency of perovskite solar cells. The researchers have shown how the introduction of graphene and graphene oxide doped with lithium atoms (GO-Li) into a perovskite-based cell may increase its conversion efficiency, as both the carrier recombination dynamics and the defect density of the perovskite are considerably improved.

The scientists used graphene doped mesoporous TiO2 (G+mTiO2) with the addition of a lithium-neutralized graphene oxide (GO-Li) interlayer as ETL. They found that the carrier collection efficiency is increased by about a factor two with respect to standard mTiO2.

Two studies led by teams at the Department of Energy's Oak Ridge National Laboratory have shown that treating a complex oxide crystal with either heat or chemicals caused different atoms to segregate on the surface (surface reconstruction) - creating catalysts with dissimilar behaviors ultimately yielding distinct products. This technique may enable catalyst designers to drive industrially important chemical reactions to improve yields of desired products and reduce unwanted products so post-reaction separation costs can be significantly diminished.

The researchers surveyed four perovskite catalysts. The tests showed that treating a perovskite with heat resulted in a catalyst with more A atoms on its surface, while treating the same perovskite with chemicals instead produced more B atoms on the surface.