P-type tetrathiafulvalene derivative as the interface modification layer in non-fullerene organic solar cells with high performance

Interfacial layers between active layer and electrodes are essential for achieving high performance in organic solar cells. Herein, an effective anode interface modification material, TTF-PZ was synthesized and combined with PEDOT:PSS using as hole transporting bilayer. The bilayer-containing routine solar cell consists of PM6: Y6 bulk heterojunction delivered an increased PCE of 15.84% and an impressive J sc of 26.19 mA/cm 2 . The underlying mechanisms of such improvement can be summarized as below: the optimization of the active layer morphology, effective charge extraction, and decreased charge recombination. This work confirms the possibility that TTF-PZ could be used as a hole transport material to obtain high performance in organic photovoltaic field. • A non-planar conjugated TTF-PZ used as buffer layers in PM:Y6 organic solar cells for the first time. • The device based on TTF-PZ/PEDOT:PSS bilayered HTLs yielded a 15.84% PCE with an J sc of 26.19 mA/cm 2 . • The reason for the higher J sc with bilayer structure was confirmed.