Identifying structure–absorption relationships and predicting absorption strength of non-fullerene acceptors for organic photovoltaics

Abstract

Non-fullerene acceptors (NFAs) are excellent light harvesters, yet the origin of such high optical extinction is not well understood. In this work, we investigate the absorption strength of NFAs by...

Asymmetric side-chain substitution enables a 3D network acceptor with hydrogen bond assisted crystal packing and enhanced electronic coupling for efficient organic solar cells

“…From BTP-PhC6 to BTP-PhC6-C11 to Y6 , the absorption strength gradually increases, which may be related to the gradual improvement of the molecular planarity. 59 From solutions to films, Y6 and BTP-PhC6-C11 exhibit similar and more remarkable redshifts (85 nm for Y6 and 84 nm for BTP-PhC6-C11 ) relative to that of BTP-PhC6 (77 nm), which are ascribed to the distinct aggregation behavior of these three SMAs in the solid state. The extinction coefficients of Y6 , BTP-PhC6-C11 , and BTP-PhC6 in the solid state were about 1.07 × 10 5 , 1.05 × 10 5 and 0.98 × 10 5 cm −1 , respectively, which exhibits the same trend as that in CF solution.…”

“…From BTP-PhC6 to BTP-PhC6-C11 to Y6, the absorption strength gradually increases, which may be related to the gradual improvement of the molecular planarity. 59 From solutions to films, Y6 and BTP-PhC6-C11 exhibit similar and more remarkable redshifts (85 nm for Y6 and 84 nm for BTP-PhC6-C11) relative to that of BTP-PhC6 (77 nm), which are ascribed to the distinct aggregation behavior of these three SMAs in the solid state.…”

Opportunities and challenges for machine learning to select combination of donor and acceptor materials for efficient organic solar cells

“…High absorption should, in principle, lead to strong emission due to the reciprocity relationship between absorption and emission, lowering nonradiative energy losses and benefiting open-circuit voltage. For identifying structure–absorption relationship, Nelson et al 141 investigated 500 unique organic molecules with DFT and TDDFT to study absorption strength and unravel structural features that lead to high absorption strength. The authors found that the absorption strength calculated experimentally and by TDDFT is in good agreement for NFAs and fullerene and suggested the use of TDDFT calculations for further modeling.…”

Active Discovery of Donor:Acceptor Combinations For Efficient Organic Solar Cells

“…16,17 ML models have been used in OSCs to investigate novel active materials and the information concealed in their chemical structures. 18 Traditionally, trialand-error approaches based on intuition have remained the primary way to design novel materials. It would take years to explore a large chemical space of materials.…”

“…Nowadays, machine learning (ML) is gaining much attention, given its ability to accelerate productivity and material discovery. , ML models have been used in OSCs to investigate novel active materials and the information concealed in their chemical structures . Traditionally, trial-and-error approaches based on intuition have remained the primary way to design novel materials.…”