In this article, we report the synthesis of bifunctional Au-Fe(3)O(4) nanoparticles that are formed by chemical bond linkage. Due to the introduction of Au nanoparticles, the resulting bifunctional Au-Fe(3)O(4) nanoparticles can be easily modified with other functional molecules to realize various nanobiotechnological separations and detections. Here, as an example, we demonstrate that as-prepared Au-Fe(3)O(4) nanoparticles can be modified with nitrilotriacetic acid molecules through Au-S interaction and used to separate proteins simply with the assistance of a magnet. Bradford protein assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were performed to examine the validity of the separation procedure, and the phosphate determination method suggested that the as-separated protein maintained catalytic activity. This result shows the efficiency of such a material in protein separation and suggests that its use can be extended to magnetic separation of other biosubstances. Moreover, this synthetic strategy paves the way for facile preparation of diverse bifunctional and even multifunctional nanomaterials.

Herein, trifluoromethylation has proven to be an effective strategy for ultra-narrow band-gap NFAs. A PCE of 15.59% is achieved from BTIC-CF 3 -g-based devices, which is the highest value in reported ultra-narrow band-gap acceptors. A ternary device with 16.50% efficiency is also obtained, resulting from its red-shifted absorption. Meanwhile, the single-crystal structure of BTIC-CF 3 -g has been successfully presented, which gives a deep understanding of the solid-state molecular packings in these highly efficient acceptors.

As a common feature in a majority of malignant tumors, hypoxia has become the Achilles’ heel of photodynamic therapy (PDT). The development of type‐I photosensitizers that show hypoxia‐tolerant PDT efficiency provides a straightforward way to address this issue. However, type‐I PDT materials have rarely been discovered. Herein, a π‐conjugated molecule with A–D–A configuration, COi6‐4Cl, is reported. The H2O‐dispersible nanoparticle of COi6‐4Cl can be activated by an 880 nm laser, and displays hypoxia‐tolerant type I/II combined PDT capability, and more notably, a high NIR‐II fluorescence with a quantum yield over 5%. Moreover, COi6‐4Cl shows a negligible photothermal conversion effect. The non‐radiative decay of COi6‐4Cl is suppressed in the dispersed and aggregated state due to the restricted molecular vibrations and distinct intermolecular steric hindrance induced by its four bulky side chains. These features make COi6‐4Cl a distinguished single‐NIR‐wavelength‐activated phototheranostic material, which performs well in NIR‐II fluorescence‐guided PDT treatment and shows an enhanced in vivo anti‐tumor efficiency over the clinically approved Chlorin e6, by the equal stresses on hypoxia‐tolerant anti‐tumor therapy and deep‐penetration imaging. Therefore, the great potential of COi6‐4Cl in precise PDT cancer therapy against hypoxia challenges is demonstrated.

To elevate the performance of polymer solar cells (PSC) processed by non‐halogenated solvents, a dissymmetric fused‐ring acceptor BTIC‐2Cl‐γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X‐ray crystallographic data suggests that BTIC‐2Cl‐γCF3 has a 3D network packing structure as a result of H‐ and J‐aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB‐TF was used as a donor, the toluene‐processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non‐halogenated solvents. Compared to its symmetric counterparts BTIC‐4Cl and BTIC‐CF3‐γ, the dissymmetric BTIC‐2Cl‐γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo‐stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi‐transparent building integrated photovoltaics (ST‐BIPV).

A chlorinated acceptor with 2-butyloctyl side chains and a 3D interpenetrated structure in the single crystal shows excellent PCE up to 16.43%.

Bulk heterojunction (BHJ) organic solar cells (OSCs) have achieved great success because they overcome the shortcomings of short exciton diffusion distances. With the progress in material innovation and device technology, the efficiency of BHJ devices is continually being improved. For some special photovoltaic material systems, it is difficult to manipulate the miscibility and morphology of blend films, and this results in moderate, even poor device performance. Quasiplanar heterojunction (Q‐PHJ) OSCs have been proposed to exploit the excellent photovoltaic properties of these materials. An OSC with BTIC‐BO‐4Cl has a 3D interpenetrating network structure with multiple channels that can facilitate the exciton diffusion and charge transport, and BTIC‐BO‐4Cl is therefore a good candidate for Q‐PHJ OSCs. In this work, a D18:BTIC‐BO‐4Cl‐based Q‐PHJ device is fabricated. The exciton diffusion lengths of D18 and BTIC‐BO‐4Cl are in accord with the requirements of the Q‐PHJ device and the efficiency of Q‐PHJ device is as high as 17.60%. This study indicates that the Q‐PHJ architecture can replace the BHJ architecture to produce excellent OSCs for certain unique donors and acceptors, providing an alternative approach to photovoltaic material design and device fabrication.

The design of polymer acceptors plays an essential role in the performance of all‐polymer solar cells. Recently, the strategy of polymerized small molecules has achieved great success, but most polymers are synthesized from the mixed monomers, which seriously affects batch‐to‐batch reproducibility. Here, a method to separate γ‐Br‐IC or δ‐Br‐IC in gram scale and apply the strategy of monomer configurational control in which two isomeric polymeric acceptors (PBTIC‐γ‐2F2T and PBTIC‐δ‐2F2T) are produced is reported. As a comparison, PBTIC‐m‐2F2T from the mixed monomers is also synthesized. The γ‐position based polymer (PBTIC‐γ‐2F2T) shows good solubility and achieves the best power conversion efficiency of 14.34% with a high open‐circuit voltage of 0.95 V when blended with PM6, which is among the highest values recorded to date, while the δ‐position based isomer (PBTIC‐δ‐2F2T) is insoluble and cannot be processed after parallel polymerization. The mixed‐isomers based polymer, PBTIC‐m‐2F2T, shows better processing capability but has a low efficiency of 3.26%. Further investigation shows that precise control of configuration helps to improve the regularity of the polymer chain and reduce the π–π stacking distance. These results demonstrate that the configurational control affords a promising strategy to achieve high‐performance polymer acceptors.

The concept of bromination for organic solar cells has received little attention. However, the electron withdrawing ability and noncovalent interactions of bromine are similar to those of fluorine and chlorine atoms. A tetra‐brominated non‐fullerene acceptor, designated as BTIC‐4Br, has been recently developed by introducing bromine atoms onto the end‐capping group of 2‐(3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene) malononitrile and displayed a high power conversion efficiency (PCE) of 12%. To further improve its photovoltaic performance, the acceptor is optimized either by introducing a longer alkyl chain to the core or by modulating the numbers of bromine substituents. After changing each end‐group to a single bromine, the BTIC‐2Br‐m‐based devices exhibit an outstanding PCE of 16.11% with an elevated open‐circuit voltage of Voc = 0.88 V, one of the highest PCEs reported among brominated non‐fullerene acceptors. This significant improvement can be attributed to the higher light harvesting efficiency, optimized morphology, and higher exciton quenching efficiencies of the di‐brominated acceptor. These results demonstrate that the substitution of bromine onto the terminal group of non‐fullerene acceptors results in high‐efficiency organic semiconductors, and promotes the use of the halogen‐substituted strategy for polymer solar cell applications.