Novel Low-Bandgap Organic Dyads Derived from Diketopyrrolopyrrole for Efficient Single-Component Organic Solar Cells

Abstract

In order to attain high performance in single-component organic solar cells (SCOSCs), it requires the designing of light-harvesting structures that can absorb light across a wide range from visible to near-infrared (NIR) wavelengths. In this investigation, two novel dyad materials, denoted as SPS-BF-Full and SPS-BT-Full are designed and synthesized, consisting of covalently linked benzofuran (BF) and benzothiophene (BT) functionalized thiophene–diketopyrrolopyrrole (TDPP) as donor and N-methyl fullero[60]pyrrolidine as the acceptor, respectively. The incorporation of a phenyl bridge between TDPP and fullero[60]pyrrolidine enhances light absorption in SPS-BF-Full and SPS-BT-Full, resulting to a high short-circuit density (J_SC). Consequently, the SCOSCs utilizing SPS-BT-Full and SPS-BF-Full attained overall power conversion efficiency (PCE) of 6.28 and 7.35%, respectively. The high photovoltaic performance of OSCs utilizing SPS-BF-Full is mainly attributed to its higher external quantum efficiency and balanced hole and electron mobility (μ_e/μ_h = 1.39), along with imporved charge carrier extraction, revealing more effective charge transport in comparison to SPS-BT-Full counterparts.