New Low Bandgap Dithienylbenzothiadiazole Vinylene Based Copolymers: Synthesis and Photovoltaic Properties

What We have Learnt from PM6:Y6

Over the past three years, remarkable advancements in organic solar cells (OSCs) have emerged, propelled by the introduction of Y6-an innovative A-DA'D-A type small molecule non-fullerene acceptor (NFA). This review provides a critical discussion of the current knowledge about the structural and physical properties of the PM6:Y6 material combination in relation to its photovoltaic performance. The design principles of PM6 and Y6 are discussed, covering charge transfer, transport, and recombination mechanisms. Then, the authors delve into blend morphology and degradation mechanisms before considering commercialization. The current state of the art is presented, while also discussing unresolved contentious issues, such as the blend energetics, the pathways of free charge generation, and the role of triplet states in recombination. As such, this review aims to provide a comprehensive understanding of the PM6:Y6 material combination and its potential for further development in the field of organic solar cells. By addressing both the successes and challenges associated with this system, this review contributes to the ongoing research efforts toward achieving more efficient and stable organic solar cells.

Mechanochemiluminescent hydrogels for real-time visualization of chemical bond scission

Quantitative and real-time characterization of mechanically induced bond scission events taken place in polymeric hydrogels is essential to uncover their fracture mechanics. Herein, a class of mechanochemiluminescent swelling hydrogels have been synthesized through a facile micellar copolymerization method using chemiluminescent bis(adamantyl)-1,2-dioxetane (Ad) as a crosslinker. This design and synthetic strategy ensure intense mechanochemiluminescence from Ad located in a hydrophobic network inside micelles. Moreover, the mechanochemiluminescent colors can be tailored from blue to red by mixing variant acceptors. Taking advantages of the transient nature of dioxetane chemiluminescence, the damage distribution and crack evolution of the hydrogels can be visualized and analyzed with high spatial and temporal resolution. The results demonstrate the strengths of the Ad mechanophore and micellar copolymerization method in the study of damage evolution and fracture mechanism of swelling hydrogels.

Separation performance of dithienyl benzothiadiazole-based stationary phases for capillary gas chromatography

Two new TBT-based stationary phases (TBT-AA, TBT-AC12) exhibited high-resolution performance for aliphatic and aromatic isomers.

Direct Arylation Strategies in the Synthesis of π-Extended Monomers for Organic Polymeric Solar Cells

π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attention. Direct arylation reactions for the production of the π-extended scaffolds are gaining importance, bearing clear advantages over traditional carbon-carbon forming methodologies. Although their use in the final polymerization step is already established, there is a need for improving synthetic accessibility to implement them also in the monomer synthesis. In this review, we discuss recent examples highlighting this useful strategy.

Efficient synthesis and photovoltaic properties of highly rigid perylene-embedded benzothiazolyls

Perylene-embedded benzothiazolyls, designed by 2D-fusing of dithienylbenzothiadiazoles, have been synthesized and characterized as new electron-accepting building-blocks for organic photovoltaic applications.

Synthesis of conjugated polymers via an exclusive direct-arylation coupling reaction: a facile and straightforward way to synthesize thiophene-flanked benzothiadiazole derivatives and their copolymers

Thiophene-flanked benzothiadiazole derivatives and their copolymers were synthesized via exclusive direct-arylation coupling reactions.

Hyperbranched fluorene-alt-carbazole copolymers with spiro[3.3]heptane-2,6-dispirofluorene as the core and their application in white polymer light-emitting devices

A potential hyperbranched structure with 2,7-fluorene-alt-3,6-carbazole and 4,7-dithienyl-2,1,3-benzothiadiazole branches, and a three-dimensional-structured spiro[3.3]heptane-2,6-dispirofluorene core is synthesized for efficient and stable WPLEDs.

Fluorene-based hyperbranched copolymers with spiro[3.3]heptane-2,6-dispirofluorene as the conjugation-uninterrupted branching point and their application in WPLEDs

Spiro[3.3]heptane-2,6-dispirofluorene as a three-dimensional, conjugation-uninterrupted branching point helps to enhance the electroluminescent performance of polyfluorene-based white-light-emitting hyperbranched copolymers.

Synthetic Aspects and Electro-Optical Properties of Fluorinated Arylenevinylenes for Luminescence and Photovoltaics

In this review, the main synthetic aspects and properties of fluorinated arylenevinylene compounds, both oligomers and polymers, are summarized and analyzed. Starting from vinyl organotin derivatives and aryl halides, the Stille cross-coupling reaction has been successfully applied as a versatile synthetic protocol to prepare a wide series of π-conjugated compounds, selectively fluorinated on the aromatic and/or vinylene units. The impact of fluoro-functionalization on properties, the solid state organization and intermolecular interactions of the synthesized compounds are discussed, also in comparison with the non-fluorinated counterparts. Luminescent and photovoltaic applications are also discussed, highlighting the role of fluorine on the performance of devices.

Low bandgap isoindigo-based copolymers: design, synthesis and photovoltaic applications

Three low bandgap isoindigo-based conjugated polymers were synthesized. The polymer films exhibit broad absorption bands in the wavelength region from 300 nm to 810 nm. PBDTID exhibited relatively better photovoltaic properties with a PCE of up to 0.9%.