Lithium-Ion Endohedral Fullerene (Li+@C-60) Dopants in Stable Perovskite Solar Cells Induce Instant Doping and Anti-Oxidation

摘要

Herein, we report use of [Li+@C-60]TFSI- as a dopant for spiro-MeOTAD in lead halide perovskite solar cells. This approach gave an air stability nearly 10-fold that of conventional devices using Li+TFSI-. Such high stability is attributed to the hydrophobic nature of [Li+@C-60]TFSI- repelling moisture and absorbing intruding oxygen, thereby protecting the perovskite device from degradation. Furthermore, [Li+@C-60]TFSI- could oxidize spiro-MeOTAD without the need for oxygen. The encapsulated devices exhibited outstanding air stability for more than 1000h while illuminated under ambient conditions.