The unique properties of organic-inorganic hybrid perovskite materials make them promising candidates for developing next-generation photovoltaic cells for commercial applications to compete with silicon solar cells. Inverted planar structure perovskite solar cells (PSCs), due to their low temperature precessing and lack of hysteretic problems, are attracting increased attention by researchers around the world. Fullerene derivatives are the most widely used electron transporting materials (ETMs) in inverted planar perovskite solar cells, especially [6,6]-phenyl-C₆₁-butyric acid methylester (PC₆₁BM), which exhibits very good performance. However, the influence of adducts on fullerene-based PSCs performance has not been fully explored to date. Here, new C₆₀ and C₇₀ fullerene derivatives were synthesized in high yields via Bingel reactions at room temperature and incorporated into CH₃NH₃PbI₃ perovskite solar cells as electron transporting materials.

Figure 1. Synthesis of C₆₀ and C₇₀ fullerene derivatives via Bingel reaction.