An Optimized Fibril Network Morphology Enables High-Efficiency and Ambient-Stable Polymer Solar Cells.

Morphological stability is crucially important for the long-term stability of polymer solar cells (PSCs). Many high-efficiency PSCs suffer from metastable morphology, resulting in severe device degradation. Here, a series of copolymers is developed by manipulating the content of chlorinated benzodithiophene-4,8-dione (T1-Cl) via a random copolymerization approach.

A General Approach for Lab-to-Manufacturing Translation on Flexible Organic Solar Cells.

The blossoming of organic solar cells (OSCs) has triggered enormous commercial applications, due to their high-efficiency, light weight, and flexibility. However, the lab-to-manufacturing translation of the praisable performance from lab-scale devices to industrial-scale modules is still the Achilles' heel of OSCs. In fact, it is urgent to explore the mechanism of morphological evolution in the bulk heterojunction (BHJ) with different coating/printing methods.

An EPDM/MVQ polymer blend based magnetorheological elastomer with good thermostability and mechanical performance.

Magnetorheological elastomers (MREs) with outstanding magnetic-control properties are highly desirable for applications such as vibration attenuation, smart sensing, and soft robots. However, the low strength and thermolability of these materials still restrict their application in attenuating the vibration of large-scale devices. In this paper, we prepared an MRE based on ethylene-propylene-diene monomer (EPDM)/methylvinyl silicone rubber (MVQ) polymer blends.

Morphology Control Enables Efficient Ternary Organic Solar Cells.

Ternary organic solar cells are promising alternatives to the binary counterpart due to their potential in achieving high performance. Although a growing number of ternary organic solar cells are recently reported, less effort is devoted to morphology control. Here, ternary organic solar cells are fabricated using a wide-bandgap polymer PBT1-C as the donor, a crystalline fused-ring electron acceptor ITIC-2Cl, and an amorphous fullerene derivative indene-C bisadduct (ICBA) as the acceptor.

Vertical Stratification Engineering for Organic Bulk-Heterojunction Devices.

High-efficiency organic solar cells (OSCs) can be produced through optimization of component molecular design, coupled with interfacial engineering and control of active layer morphology. However, vertical stratification of the bulk-heterojunction (BHJ), a spontaneous activity that occurs during the drying process, remains an intricate problem yet to be solved. Routes toward regulating the vertical separation profile and evaluating the effects on the final device should be explored to further enhance the performance of OSCs.

Improved Glass Transition Temperature towards Thermal Stability via Thiols Solvent Additive versus DIO in Polymer Solar Cells.

The halogen-free solvent additive, 1,4-butanedithiol (BT) has been incorporated into PTB7-Th:PC BM, leading to higher power conversion efficiency (PCE) value as well as substantially enhanced thermal stability, as compared with the traditional 1,8-diiodooctane (DIO) additive. More importantly, the improved thermal stability after processing with BT contributes to a higher glass transition temperature (T ) of PTB7-Th, as determined by dynamic mechanical analysis. After thermal annealing at 130 °C in nitrogen atmosphere for 30 min, the PCE of the specimen processed with BT reduces from 9.

Butanedithiol Solvent Additive Extracting Fullerenes from Donor Phase To Improve Performance and Photostability in Polymer Solar Cells.

In this work, we demonstrated that the excited poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2,6-diyl)] (PTB7-Th) will be degraded by [6,6]-phenyl-C-butyric acid methyl ester (PCBM) or photolysis fragment of 1,8-diiodooctane (DIO) in the presence of oxygen and under irradiation of red light. From the previous reports, the fragment of DIO may be involved in the reaction directly. Our work indicates the PCBM is not directly involved in the reaction, but is acting as a catalyst to promote the reaction of excited donors with oxygen.

Surface treatment by binary solvents induces the crystallization of a small molecular donor for enhanced photovoltaic performance.

The surface treatment of the active layer with binary solvents composed of methanol (MeOH) and 1-chloronaphthalene (CN), was demonstrated to effectively improve the power conversion efficiency (PCE) from 2.4% to 6.5% for p-DTS(FBTTh2)2:PC71BM based small molecular solar cells.

Fusing three perylenebisimide branches and a truxene core into a star-shaped chromophore with strong two-photon excited fluorescence and high photostability.

A novel star-shaped chromophore, Tr-PBI, was constructed by fusing three perylenebisimide branches and a truxene core. Tr-PBI exhibits high photostability and excellent two-photon properties: the maximum of δ(TPA) is 11,000 GM at 990 nm and fluorescence quantum efficiency Φ is 0.40 in THF.

Fused perylenebisimide-carbazole: new ladder chromophores with enhanced third-order nonlinear optical activities.

A series of ladder chromophores featuring planar structures of fused perylenebisimide and carbazole have been efficiently synthesized via photocyclization under sun light. Compared to N,N'-bis(3-pentyl) perylenebisimide (PBI-1), they show remarkably enhanced nonlinear properties.