Graphite particle modification on spiro- OMeTAD to enhance the power conversion properties of perovskite solar cells

Abstract Graphite nanoparticles are blended into Spiro-OMeTAD solution to enhance the film quality of the hole-transporting-layer (HTL) and the performance of perovskite solar cells (PSCs). It is observed that the graphite particles help increase the power conversion efficiency (PCE) from 19.25 (± 1.13) % to 20.81 (± 0.77) % (optimized at 22.01%). Meanwhile, a lower hysteresis index (HI) is observed. The enhanced performance is attributed to the interaction between graphite and Spiro-OMeTAD. The conductive graphite nanoparticles could improve the film continuity of the Spiro-OMeTAD basing HTL, which accelerates electron extraction and reduces charge recombination processes, contributing to PCE improvement.