Small molecule acceptors with a ladder-like core for high-performance organic solar cells with low non-radiative energy losses

Abstract

Three noncovalently fused-ring electron acceptors with good solubility, near-infrared absorption, and high electron mobility are precisely designed for high-efficiency OSCs.

Modulating Energy Level on an A‐D‐A′‐D‐A‐Type Unfused Acceptor by a Benzothiadiazole Core Enables Organic Solar Cells with Simple Procedure and High Performance

“…The synthetic routes to two UFAs BFC‐4F and BOC‐4F are shown in Scheme , which utilizes an extremely simple procedure similar to Bo and co‐worker's contemporary report. [ 45 ] To begin with, 4,7‐dibromo‐5,6‐difluorobenzo[ c ][1,2,5]thiadiazole or 4,7‐dibromo‐5,6‐dimethoxybenzo[ c ][1,2,5]thiadiazole was undergone Stille cross‐coupling reaction with (4,4‐bis(2‐ethylhexyl)‐4 H ‐cyclopenta[2,1‐ b :3,4‐ b′ ]dithiophen‐2‐yl)trimethylstannane, respectively. The resultant coupling products were subsequently subjected to formylation through Vilsmeier–Haack reactions to obtain the dialdehyde precursors.…”

“…The synthetic routes to two UFAs BFC-4F and BOC-4F are shown in Scheme 1, which utilizes an extremely simple procedure similar to Bo and co-worker's contemporary report. [45] To begin with, 4,7-dibromo-5,6-difluorobenzo precursors. Finally, the dialdehyde intermediates were conducted with (5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (2F-IC) to yield BFC-4F and BOC-4F through Knoevenagel reactions.…”

Molecular Engineering and Morphology Control of Polythiophene:Nonfullerene Acceptor Blends for High‐Performance Solar Cells

“…Recently developed unfused building block-based nonfullerene acceptors, which can be easily synthesized from commercial materials, exhibit relatively low cost. [170][171][172][173][174][175][176][177] Through incorporating intramolecular noncovalent interaction like F-H and O-S, the unfused building block-based nonfullerene acceptors are able to attain nearly planar molecular geometry and achieve high electron mobility. In addition, absorption and energy levels of this type of nonfullerene acceptors can be easily tuned by modification of the building blocks.…”

An A-D-A′-D-A type unfused nonfullerene acceptor for organic solar cells with approaching 14% efficiency

“…For the design of UFAs, the selection of A′ (and D′) unit is a key issue, which is essential for regulating energy levels, light-harvest ability, intramolecular interactions, and intermolecular packing behavior. At present, many research groups have done a lot of meaningful work on the selection of A′ (and D′) units, such as para-difluorobenzene [7], para-dialkoxybenzene [9], benzobis(thiazole) [14], 5,6dialkoxy-substituted benzothiadiazole [17], 3,4-difluorothiophene [8], and thieno [3,4-c]pyrrole-4,6-dione [20]. However, the PCEs of UFAs have still lagged far behind those of FRAs.…”