Synthesis of Perfluoroalkyl End-Functionalized Poly(3-hexylthiophene) and the Effect of Fluorinated End Groups on Solar Cell Performance

A Polyfluoroalkyl-Containing Non-fullerene Acceptor Enables Self-Stratification in Organic Solar Cells

The elaborate control of the vertical phase distribution within an active layer is critical to ensuring the high performance of organic solar cells (OSCs), but is challenging. Herein, a self-stratification active layer is realised by adding a novel polyfluoroalkyl-containing non-fullerene small-molecule acceptor (NFSMA), EH-C₈ F₁₇ , as the guest into PM6:BTP-eC9 blend. A favourable vertical morphology was obtained with an upper acceptor-enriched thin layer and a lower undisturbed bulk heterojunction layer. Consequently, a power conversion efficiency of 18.03 % was achieved, higher than the efficiency of 17.40 % for the device without EH-C₈ F₁₇ . Additionally, benefiting from the improved charge transport and collection realised by this self-stratification strategy, the OSC with a thickness of 350 nm had an impressive PCE of 16.89 %. The results of the study indicate that polyfluoroalkyl-containing NFSMA-assisted self-stratification within the active layer is effective for realising an ideal morphology for high-performance OSCs.

Construction of well-defined difluoromethylthio-containing amphiphilic homopolymers by RAFT polymerization

A well-defined difluoromethylthio-containing amphiphilic homopolymer with a lower T_g was obtained by RAFT polymerization.

Chain conformations and phase behavior of conjugated polymers

Conjugated polymers may play an important role in various emerging optoelectronic applications because they combine the chemical versatility of organic molecules and the flexibility, stretchability and toughness of polymers with semiconducting properties. Nevertheless, in order to achieve the full potential of conjugated polymers, a clear description of how their structure, morphology, and macroscopic properties are interrelated is needed. We propose that the starting point for understanding conjugated polymers includes understanding chain conformations and phase behavior. Efforts to predict and measure the persistence length have significantly refined our intuition of the chain stiffness, and have led to predictions of nematic-to-isotropic transitions. Exploring mixing between conjugated polymers and small molecules or other polymers has demonstrated tremendous advancements in attaining the needed properties for various optoelectronic devices. Current efforts continue to refine our knowledge of chain conformations and phase behavior and the factors that influence these properties, thereby providing opportunities for the development of novel optoelectronic materials based on conjugated polymers.

Poly(3-hexylthiophene) End-Functionalization via Quenching Resulting in Heteroatom-Bond Formation

End-functionalized poly(3-hexylthiophene) (P3HT) has contributed to continued advancements in conjugated polymer applications, especially within organic electronics. P3HT synthesized using Kumada catalyst-transfer polymerization (KCTP) has many favourable attributes such as controlled molecular weight, high regioregularity, and narrow dispersity. With the addition of reactive end-groups, P3HT plays an important role in advancing the development of hybrid materials and preparation of block copolymers. Exploring methods of end-functionalization that result in heteroatom-bond formation, giving a non-carbon atom bonded to the terminal thiophene, could help control and understand the p–n junction of hybrid materials. This research highlight focuses on the development of a novel and facile way of end-functionalizing P3HT with chalcogens.

Expanding the light absorption of poly(3-hexylthiophene) by end-functionalization with π-extended porphyrins

Poly(3-hexylthiophene)s end-functionalized with π-extended porphyrins show a broad absorption profile up to 700 nm and a fibrillar microstructure tuned by the porphyrin molar ratio.

Synthesis of well-defined α-fluorinated alkyl ester, ω-carboxyltelechelic polystyrenes and fabrication of their hydrophobic highly ordered porous films and microspheres

Porous films and microspheres of α-fluorinated alkyl ester, ω-carboxyl telechelic polystyrenes synthesized via combining aminolysis of RAFT-polystyrene with thiol–ene “click” reaction.

Accessing conjugated polymers with precisely controlled heterobisfunctional chain ends via post-polymerization modification of the OTf group and controlled Pd(0)/t-Bu3P-catalyzed Suzuki cross-coupling polymerization

Accessing of conjugated polymers with precisely controlled heterobisfunctional chain ends was achieved via the post-polymerization modification of the triflate (OTf) group.

Monotelechelic poly(p-phenylenevinylene)s by ring opening metathesis polymerisation

High molecular weight poly(p-phenylenevinylene)s with a single reactive end group are reported that act as excellent macroinitiators in block copolymer synthesis.