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Organic solar cells (OSCs) have attracted extensive attention from both academia and industry in recent years due to their remarkable improvement in power conversion efficiency (PCE). However, the Golden Triangle (the balance of efficiency‐stability‐cost) required for large‐scale industrialization of OSCs still remains a great challenge. Here, a new nonfused‐ring electron acceptor (NFREA) BF and its polymerized counterpart PBF were designed and synthesized, and their photovoltaic performance, storage stability and material cost were systematically investigated. When blended with a widely‐used polymer donor PBDB‐T, the PBF‐based all‐polymer solar cell (all‐PSC) displayed a record high PCE of 12.61% for polymerized NFREAs (PNFREAs) with an excellent stability (95.2% of initial PCE after 800 h storage), superior to the BF counterpart. Impressively, PBF‐based all‐PSC possesses the highest industrial figure‐of‐merit (i‐FOM) value of 0.309 based on an efficiency‐stability‐cost evaluation, in comparison to several representative OSC systems (such as PM6:Y6 and PBDB‐T:PZ1). This work provides an insight into the balance of efficiency, stability, and cost, and also indicates that the PNFREAs are promising materials toward the commercial application of OSCs. [ABSTRACT FROM AUTHOR]

The power conversion efficiencies (PCEs) of all‐polymer solar cells (all‐PSCs) have already exceeded 17%. However, the limited absorption range of an all‐polymer system results in significantly reduced short‐circuit current density (Jsc), which eventually influences the PCE improvement. To broaden the light absorption of polymer acceptors, herein, benzotriazole is introduced in the core unit of small molecule acceptors and thus two narrow‐bandgap polymer acceptors named PTz‐BO and PTz‐C11 featuring the same molecular backbone and different side‐chain length are synthesized. Compared with PTz‐C11, the PTz‐BO based‐all PSCs deliver a slightly reduced Jsc, a large open‐circuit voltage (Voc) and a low voltage loss below 0.50 V. Moreover, ternary all‐PSCs are constructed by introducing PTz‐C11 as a guest component. Benefiting from the reduced recombination, improved exciton generation and dissociation, and balanced charge transport, a high efficiency of 16.58% is obtained for the ternary all‐PSCs, with a high Jsc over 25 mA cm−2 without sacrificing the Voc. Such result represents the highest efficiency reported for benzotriazole‐based all‐PSCs in the literature thus far. This work demonstrates the great potential of benzotriazole for the synthesis of efficient narrow‐bandgap polymer acceptors. [ABSTRACT FROM AUTHOR]

The development of organic solar cells (OSCs) with thick active layers is of crucial importance for the roll-to-roll printing of large-area solar panels. Unfortunately, increasing the active layer thickness usually results in a significant reduction in efficiency. Herein, we fabricated efficient thick-film OSCs with an active layer consisting of one polymer donor and two non-fullerene acceptors. The two acceptors were found to possess enlarged exciton diffusion length in the mixed phase, which is beneficial to exciton generation and dissociation. Additionally, layer by layer approach was employed to optimize the vertical phase separation. Benefiting from the synergetic effects of enlarged exciton diffusion length and graded vertical phase separation, an efficiency of 17.31% (certified value of 16.9%) is obtained for the 300 nm-thick OSC, with a short-circuit current density of 28.36 mA cm−2, and a high fill factor of 73.0%. Moreover, the device with an active layer thickness of 500 nm also shows an efficiency of 15.21%. This work provides valuable insights into the fabrication of OSCs with thick active layers. Exciton diffusion length and graded vertical phase separation of the active layer play a critical role in the realization of high-performance thick-film organic solar cells (OSCs). Here, authors demonstrated OSCs with an efficiency of 17.31%, with an active layer thickness of around 300 nm. [ABSTRACT FROM AUTHOR]

This article discusses the challenge of industrializing organic solar cells and the need to balance efficiency, stability, and cost. The authors present a polymer acceptor called PBF, which was created using a polymerized nonfused-ring electron acceptor strategy. This polymer acceptor achieved a high efficiency of 12.61%, excellent stability, and low cost, making it a promising option for industrial applications. The authors compare the performance of PBF to other reputable systems and highlight its superior figure-of-merit. [Extracted from the article]

Side-chain engineering is one of the most promising ways to develop non-fullerene acceptors (NFAs) for organic solar cells. In this work, we designed and synthesized a novel acceptor IT-BnC6-4F by introducing methylene group between the phenyl group and the sp3 hybrid carbon atoms of central conjugated cores to form benzyl side chains. IT-BnC6-4F shows broader absorption spectrum and higher crystallinity than those of its analogue, IT-4F. When blended with PT2, the IT-BnC6-4F based device achieved a high power conversion efficiency (PCE) of 13.36 %, with an open-circuit voltage (V oc) of 0.87 V and a short-circuit current density (J sc) of 20.99 mA cm−2. [Display omitted] • Benzyl side chains functionalized non-fullerene acceptor was synthesized. • Substitution effects of the benzyl side chains on photovoltaic performance of the non-fullerene acceptor were investigated. • Benzyl side chains could endure the non-fullerene acceptor with broader absorption spectrum and higher crystallinity. [ABSTRACT FROM AUTHOR]