Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for flexible and wearable electronics. However, it usually suffers from low semiconducting tube purity, low device yield, and ...the mismatch between p- and n-type TFTs. Here, we report low-voltage and high-performance digital and analog CNT TFT circuits based on high-yield (19.9%) and ultrahigh purity (99.997%) polymer-sorted semiconducting CNTs. Using high-uniformity deposition and pseudo-CMOS design, we demonstrated CNT TFTs with good uniformity and high performance at low operation voltage of 3 V. We tested forty-four 2-µm channel 5-stage ring oscillators on the same flexible substrate (1,056 TFTs). All worked as expected with gate delays of 42.7 ± 13.1 ns. With these high-performance TFTs, we demonstrated 8-stage shift registers running at 50 kHz and the first tunable-gain amplifier with 1,000 gain at 20 kHz. These results show great potentials of using solution-processed CNT TFTs for large-scale flexible electronics.
The design and synthesis of advanced semiconductors is crucial for the full utilization of solar energy. Herein, colloidal selective‐epitaxial hybrid of tripartite semiconducting sulfides ...CuInS2Cd(In)SMoS2 heteronanostructures (HNs) via lateral‐ and vertical‐epitaxial growths, followed by cation exchange reactions, are reported. The lateral‐epitaxial CuInS2 and Cd(In)S enable effective visible to near‐infrared (NIR) solar spectrum absorption, and the vertical‐epitaxial ultrathin MoS2 offer sufficient edge sulfur sites for the hydrogen evolution reaction (HER). Furthermore, the integrated structures exhibit unique epitaxial‐staggered type II band alignments for continuous charge separation. They achieve the H2 evolution rate up to 8 mmol h−1 g−1, which is ≈35 times higher than bare CdS and show no deactivation after long‐term cycling, representing one of the most efficient and robust noble‐metal‐free photocatalysts. This design principle and transformation protocol open a new way for creating all‐in‐one multifunctional catalysts in a predictable manner.
A wet‐chemical strategy for the selective‐epitaxial hybrid of unique tripartite semiconducting sulfide heteronanostructures CuInS2Cd(In)SMoS2 is reported. The stepwise integrated structures demonstrate superior solar‐to‐hydrogen conversion performance due to the enhanced capabilities for solar absorption and charge separation, together with sufficient catalytically active sites.
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•A dual-functional ultrafiltration membrane containing quaternary ammonium and zwitterionic polymers was prepared.•The antifouling and antibacterial behavior of the membrane was ...studied.•The membrane showed the improved organic-/bio fouling resistance.•The membrane showed high-efficiency broad-spectrum antibacterial performance.
To overcome the organic-/bio- fouling of the membrane, a dual-functional ultrafiltration membrane containing quaternary ammonium and zwitterionic polymers via quaternization and surface radical polymerization was designed, and its antifouling and antibacterial behavior was studied. In this work, poly(vinylidene fluoride)/poly(methyl methacrylate-co-dimethylamino-2-ethyl methacrylate) (PVDF/P(MMA-co-DMAEMA)) blend membrane was quaternized by p-chloromethyl styrene (p-CMS), and the double bonds were introduced onto the membrane surface, which further participated in the polymerization of zwitterionic monomers on the membrane surface. The results indicated that the resultant membrane exhibited obviously improved hydrophilicity and weak positive charge (isoelectric point, 7.49). The membrane presented higher flux recovery ratio and lower protein adhesion compared with the pure PVDF membrane. Meanwhile, the membrane showed high-efficiency broad-spectrum antibacterial performance, that is, the bacteria killing efficiency of S. aureus and E. coli reached 98.2% and 97.0%, respectively. Moreover, the membrane effectively inhibited bacterial adhesion, which is important for the long-term antibacterial properties of membrane. This antifouling and antibacterial PVDF membrane may have potential in the long-term filtration process, especially when dealing with microbiologically contaminated water.
Wafer‐scale fabrication of high‐performance uniform organic electronic materials is of great challenge and has rarely been realized before. Previous large‐scale fabrication methods always lead to ...different layer thickness and thereby poor film and device uniformity. Herein, the first demonstration of 4 in. wafer‐scale, uniform, and high‐performance n‐type polymer monolayer films is reported, enabled by controlling the multi‐level self‐assembly process of conjugated polymers in solution. Since the self‐assembly process happened in solution, the uniform 2D polymer monolayers can be facilely deposited on various substrates, and theoretically without size limitations. Polymer monolayer transistors exhibit high electron mobilities of up to 1.88 cm2 V−1 s−1, which is among the highest in n‐type monolayer organic transistors. This method allows to easily fabricate n‐type conjugated polymers with wafer‐scale, high uniformity, low contact resistance, and excellent transistor performance (better than the traditional spin‐coating method). This work provides an effective strategy to prepare large‐scale and uniform 2D polymer monolayers, which could enable the application of conjugated polymers for wafer‐scale sophisticated electronics.
Using a multi‐level self‐assembly strategy, an n‐type polymer monolayer field‐effect transistor is obtained on wafer‐scale. These devices offers high performance, high air‐stability, and high uniformity. The strategy enhances the formation of wafer‐scale and uniform polymer monolayers. Transistor arrays on a 4 in. wafer exhibit electron mobilities of up to 1.88 cm2 V−1 s−1, among the highest reported until now for n‐type monolayer organic transistors.
Polymer self‐assembly in solution prior to film fabrication makes solution‐state structures critical for their solid‐state packing and optoelectronic properties. However, unraveling the ...solution‐state supramolecular structures is challenging, not to mention establishing a clear relationship between the solution‐state structure and the charge‐transport properties in field‐effect transistors. Here, for the first time, it is revealed that the thin‐film morphology of a conjugated polymer inherits the features of its solution‐state supramolecular structures. A “solution‐state supramolecular structure control” strategy is proposed to increase the electron mobility of a benzodifurandione‐based oligo(p‐phenylene vinylene) (BDOPV)‐based polymer. It is shown that the solution‐state structures of the BDOPV‐based conjugated polymer can be tuned such that it forms a 1D rod‐like structure in good solvent and a 2D lamellar structure in poor solvent. By tuning the solution‐state structure, films with high crystallinity and good interdomain connectivity are obtained. The electron mobility significantly increases from the original value of 1.8 to 3.2 cm2 V−1 s−1. This work demonstrates that “solution‐state supramolecular structure” control is critical for understanding and optimization of the thin‐film morphology and charge‐transport properties of conjugated polymers.
A supramolecular self‐assembly strategy is used to control the solution‐state structure of a conjugated polymer. It is revealed that the thin‐film morphology of the conjugated polymer inherits the features of their solution‐state supramolecular structures. Through “solution‐state supramolecular structure control”, the electron mobility of the polymer is boosted to 3.2 cm2 V−1 s−1, nearly doubling the original performance.
The side‐on‐end‐on coordination of N2 can be very important to activate and functionalize this very stable molecule. However, such coordination has rarely been reported. This study reports a ...gas‐phase species (a polynuclear vanadium nitride cluster anion V5N5−) that can capture N2 efficiently (12 %), and the quantum chemistry modelling suggests an unusual side‐on‐end‐on coordination. The cluster anions were generated by laser ablation and the reaction with N2 has been characterized by mass spectrometry, photoelectron imaging spectroscopy, and density functional theory calculations. The back‐donation interactions between the localized d–d bonding orbitals on the low‐coordinated dual metal (V) sites and the antibonding π* orbitals of N2 are the driving forces to adsorb N2 with a high binding energy (about 2.0 eV).
N2 fixation: The polynuclear vanadium nitride cluster anion V5N5− can capture N2 efficiently (12 %) with the unusual side‐on‐end‐on coordination. The back‐donation interactions between the localized d–d bonding orbitals on the low‐coordinated dual metal (V) sites and the antibonding π* orbitals of N2 are the driving forces to adsorb N2 with a high binding energy (about 2.0 eV).
Molecular packing in organic single crystals greatly influences their charge transport properties but can hardly be predicted and designed because of the complex intermolecular interactions. In this ...work, we have realized systematic fine-tuning of the single-crystal molecular packing of five benzodifurandione-based oligo(p-phenylenevinylene) (BDOPV)-based small molecules through incorporation of electronegative fluorine atoms on the BDOPV backbone. While these molecules all exhibit similar column stacking configurations in their single crystals, the intermolecular displacements and distances can be substantially modified by tuning of the amounts and/or the positions of the substituent fluorine atoms. Density functional theory calculations showed that the subtle differences in charge distribution or electrostatic potential induced by different fluorine substitutions play an important role in regulating the molecular packing of the BDOPV compounds. Consequently, the electronic couplings for electron transfer can vary from 71 meV in a slipped stack to 201 meV in a nearly cofacial antiparallel stack, leading to an increase in the electron mobility of the BDOPV derivatives from 2.6 to 12.6 cm2 V–1 s–1. The electron mobility of the five molecules did not show a good correlation with the LUMO levels, indicating that the distinct difference in charge transport properties is a result of the molecular packing. Our work not only provides a series of high-electron-mobility organic semiconductors but also demonstrates that fluorination is an effective approach for fine-tuning of single-crystal packing modes beyond simply lowering the molecular energy levels.
The gut microbiota plays a critical role in obesity and lipid metabolism disorder. Chokeberry (
L
) are rich in polyphenols with various physiological and pharmacological activities. We determined ...serum physiological parameters and fecal microbial components by using related kits, liquid chromatography-mass spectrometry (LC-MS) and 16S rRNA gene sequencing every 10 days. Real-time PCR analysis was used to measure gene expression of bile acids (BAs) and lipid metabolism in liver and adipose tissues. We analyzed the effects of different Chokeberry polyphenol (CBPs) treatment time on obesity and lipid metabolism in high fat diet (HFD)-fed rats. The results indicated that CBPs treatment prevents obesity, liver steatosis and improves dyslipidemia in HFD-fed rats. CBPs modulated the composition of the gut microbiota with the extended treatment time, reducing the
/
ratio (F/B ratio) and increasing the relative abundance of
,
,
and other bacterial species associated with anti-obesity properties. We found that CBPs treatment gradually decreased the total BAs pool and particularly reduced the relative content of cholic acid (CA), deoxycholic acid (DCA) and enhanced the relative content of chenodeoxycholic acid (CDCA). These changes were positively correlated
,
and negatively correlated with
,
,
. In liver and white adipose tissues, the gene expression of lipogenesis, lipolysis and BAs metabolism were regulated after CBPs treatment in HFD-fed rats, which was most likely mediated through FXR and TGR-5 signaling pathway to improve lipid metabolism. In addition, the mRNA expression of PPARγ, UCP1 and PGC-1α were upregulated markedly in interscapular brown adipose tissue (iBAT) after CBPs treatment. We confirmed that CBPs could reduce the body weight of HFD-fed rats by accelerating energy homeostasis and thermogenesis in iBAT. Finally, the fecal microbiota transplantation (FMT) experiment results demonstrated that FMT from CBPs-treated rats failed to reduce the weight of HFD-fed rats. However, FMT from CBPs-treated rats improved dyslipidemia and reshaped gut microbiota in HFD-fed rats. In conclusion, CBPs treatment improved obesity and complications by regulating gut microbiota in HFD-fed rats. The gut microbiota plays an important role in BAs metabolism after CBPs treatment, and BAs have therefore emerged as major effectors in microbe-host signaling events that influence host lipid metabolism, energy metabolism and thermogenesis.
Recently, polymer field‐effect transistors have gone through rapid development. Nevertheless, charge transport mechanism and structure‐property relationship are less understood. Here we use strong ...electron‐deficient benzodifurandione‐based poly(p‐phenylene vinylene) (BDPPV) as polymer backbone and develop six BDPPV‐based polymers (BDPPV‐C1 to C6) with various side‐chain branching positions to systematically study the side‐chain effect on device performance. All the polymers exhibited ambient‐stable n‐type transporting behaviors with the highest electron mobility of up to 1.40 cm2 V−1 s−1. The film morphologies and microstructures of all the six polymers were systematically investigated. Our results demonstrate that the interchain π–π stacking distance decreases as moving the branching position away from polymer backbones, and an unprecedentedly close π–π stacking distance down to 3.38 Å is obtained for BDPPV‐C4 to C6. Nonetheless, closer π–π stacking distance does not always correlate with higher electron mobility. Polymer crystallinity, thin film disorder, and polymer packing conformation, which all influenced by side‐chain branching position, are proved to show significant influence on device performance. Our study not only reveals that π–π stacking distance is not the decisive factor on carrier mobility in conjugated polymers but also demonstrates that side‐chain branching position engineering is a powerful strategy to modulate and balance these factors in conjugated polymers.
Six BDPPV‐based polymers with various side‐chain branching positions are synthesized and characterized in details. All the polymers exhibit ambient‐stable n‐type transporting behavior with the highest electron mobility up to 1.40 cm2 V−1 s−1. By means of multiple characterization methods, film morphology, and microstructure of all the six polymers are systematically investigated.
Planar backbone, locked conformation, and low lowest unoccupied molecular orbital level provide polymer F4BDOPV‐2T with ultrahigh electron mobilities of up to 14.9 cm2 V−1 s−1 and good air stability. ...It is found that the nonlinear transfer curves can be tuned to near‐ideal ones by changing fabrication conditions, indicating that film morphology largely contributes to the nonlinear transfer curves in high‐mobility conjugated polymers.
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