A Pyrene‐Fused Dimerized Acceptor for Ternary Organic Solar Cells with 19% Efficiency and High Thermal Stability

Abstract

A pyrene‐fused dimerized electron acceptor has been successfully synthesized and subsequently incorporated as the third component in ternary organic solar cells (OSCs). Diverging from the traditional dimerized acceptors with a linear configuration, this novel electron acceptor displays a distinctive “butterfly‐like” structure, comprising two Y‐acceptors as wings fused with a pyrene‐based backbone. The extended π‐conjugated backbone and the electron‐donating nature of pyrene enable the new acceptor to show low solubility, elevated glass transition temperature (Tg), and low‐lying frontier energy levels. Consequently, the new dimerized acceptor seamlessly integrates as the third component into ternary OSCs, enhancing electron transporting properties, reducing non‐radiative voltage loss, and elevating open‐circuit voltage. These merits have enabled the ternary OSCs to show an exceptional efficiency of 19.07%, a marked improvement compared to the 17.6% attained in binary OSCs. More importantly, the high Tg exhibited by the pyrene‐fused electron acceptor helps to stabilize the morphology of the photoactive layer thermal‐treated at 70 °C, retaining 88.7% efficiency over 600 hours. For comparison, binary OSCs experience a decline to 73.7% efficiency after the same duration. These results indicate that the “butterfly‐like” design and the incorporation of a pyrene unit is a promising strategy in the development of dimerized electron acceptors for OSCs.

Recent progress and prospects of dimer and multimer acceptors for efficient and stable polymer solar cells

“…14a). 172 The fused backbone structure of DP-BTP DSMA resulted in negligible torsion between the two Y-core units, which was advantageous for obtaining excellent light absorption and charge transport capabilities. When combined with D18 P D , D18:DP-BTP-based PSCs exhibited a high PCE of 15.08%.…”

High-Performance Annealing-Free Polythiophene-Based Organic Solar Cells Enabled by Volatile Solid Additive

“…Organic solar cells (OSCs) have captivated substantial interest due to their lightness and flexibility, large-scale manufacturing, and roll-to-roll solution coating production methodology. − Recent evolvements in refined material design and device engineering have propelled the power conversion efficiencies (PCEs) of OSCs to exceed 19%. − However, the complicate synthesis and limited scalability of high-performance photovoltaic polymers featuring a donor–acceptor alternating design significantly escalate the production costs, imposing considerable obstacles on the commercial advancement of OSCs. − In this scenario, polythiophenes (PTs)-based polymer donors, featuring simple molecular structures and low-cost synthesis processes, hold great promise for practical applications. − Unfortunately, their photovoltaic efficiency and device stability are constrained by the less-than-ideal molecular stacking and phase separation when paired with acceptor materials due to their strong crystalline properties. , …”