Incorporating Naphthalene and Halogen into Near-Infrared Double-Cable Conjugated Polymers for Single-Component Organic Solar Cells with Low-Voltage Losses

Abstract

The invention of near-infrared pedant-based double-cable conjugated polymers has demonstrated remarkable efficacy in single-component organic solar cells (SCOSCs). This work focuses on the innovative double-cable conjugated polymers aimed at attaining good absorption and suitable energy levels. Specifically, in the aromatic side units, the electron-donating (D) part is designed using a thieno[3,4-c]pyrrole-4,6-dione (TPD) as a core unit, flanked by two cyclopentadithiophene groups on either side. The electron-deficient (A) terminal groups consist of 2-(3oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene) malononitrile (NC), which can be further modified through fluorination to modulate the physical properties and packing modes of the acceptor material. The resulting double-cable conjugated polymers exhibit broad absorption spectra spanning 500−850 nm and possess lowered Frontier energy levels when incorporating fluorine elements, providing decreased voltage losses in SCOSCs. Therefore, SCOSCs fabricated using these polymers have demonstrated power conversion efficiencies ranging from 7.6 to 10.2%, in which fluorine-containing double-cable conjugated polymers showed higher PCEs due to more favorable crystalline packing, enhanced exciton dissociation probability, and charge-transporting ability.

Dimerized Nonfused Electron Acceptor Based on a Thieno[3,4-c]pyrrole-4,6-dione Core for Organic Solar Cells

“…The synthesis starts by using 1-bromohexane and 1,6-dibromohexane to react with M1 to yield compounds M2 and M3. Compound M4 was synthesized according to our previous work . Then, compounds M5 and M6 were synthesized using the Stille reaction, followed by Knoevenagel condensation to provide the acceptor RM1 and dimerized acceptor RM2.…”

Nonfused Electron Acceptors Based on the 2D-Extended Quinoxaline Core for Organic Solar Cells

“…Organic solar cells (OSCs) typically employ bulk heterojunction (BHJ) photoactive layers, where electron donors and acceptors are physically blended to utilize solar energy and convert it into electricity. Recently, there has been notable progress in the utilization of organic semiconductors, particularly those incorporating near-infrared (NIR) electron acceptors featuring the 2-(3-oxo-2,3-dihydroinden-1-ylidene) malononitrile (IC) terminal group, leading to impressive power conversion efficiencies (PCEs) surpassing 19% in single-junction devices. − Moreover, investigations pertaining to the diverse potential applications of OSCs, including but not limited to semitransparent OSCs, − indoor photovoltaic systems, − and flexible devices, − have been documented in the literature. Consequently, OSCs have emerged as highly promising tools with considerable utility in the realm of power generation and related fields.…”