Highly Efficient Organic Solar Cells Enabled by the Incorporation of a Sulfonated Graphene Doped PEDOT:PSS Interlayer

An interface modification layer plays an important role in improving the performance of organic solar cells (OSCs). The structure design or doping of electrode interlayer materials can effectively inhibit interfacial carrier recombination and improve ohmic contact between the active layer and the electrodes, which is desirable for realizing high power conversion efficiencies (PCEs). Poly( 3, 4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively used as a hole-transport layer (HTL) in OSCs. Here, a modification of PEDOT:PSS is proposed using sulfonated graphene (SG) as a secondary dopant for improving the surface morphology and conductivity. The incorporation of the SG-doped PEDOT:PSS as the HTLs in OSCs leads to the increased charge extraction and shows the best PCEs of 17.48% for PM6:Y6 devices and 18.56% for PM6:L8-BO devices. The significant improvement in device performance suggests that SG-PEDOT:PSS is a promising interfacial layer for efficient charge transport and extraction toward high-efficiency OSCs.

Automated summary

An interface modification layer is crucial for enhancing the performance of organic solar cells. This study proposes a new method using sulfonated graphene to modify PEDOT:PSS, resulting in improved surface morphology and conductivity, and increased charge extraction.