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We report the synthesis and dynamic covalent chemistry (DCvC) of an A1/A2-dimercapto-functionalized pillar[5]arene (Di-SH-P5). The introduction of thiol moieties into this macrocyclic host makes it an effective building block for making a dynamic combinatorial library (DCL), giving rise to a set of cyclic trimers with intriguing host–guest properties as the dominant constituents. [ABSTRACT FROM AUTHOR]

The safety of animal-origin foods has a major influence on human health. Although the use of veterinary drug additives (VDAs) significantly promotes the normal growth and development of animals against diseases, the excessive consumption of VDAs is always the most worrying part. Thus, realizing a direct and prompt detection of solid VDAs is highly desirable. In this study, we incorporated a functional unit of triazolo [4,5-c] pyridine (TP) in polymer semiconductors. The theoretical simulation demonstrates that TP can effectively form hydrogen bonding with the VDA molecules. Furthermore, highly sensitive polymeric field-effect transistors (PFETs) are fabricated through the configurational design of low-dimensional polymer networks (LDPNs). The conducting channel and hydrogen bonding sites of the LDPN-based PFETs could be directly exposed to the analytes, thereby effectively capturing VDA molecules and converting the stimuli into electrical signals. The obtained PFET-based solid sensors showed highly sensitive and stable detection of melamine powders at a low operation voltage of −5 V. The detection limit realized is lower than the international standards in animal feeds (2.5 ppm). These results demonstrate the promising applications of PFETs for high-efficiency and low-power-consumption sensors for solid detection or biological diagnosis. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid perovskites exhibit superior optoelectrical properties and have been widely used in photodetectors. Perovskite photodetectors with excellent detectivity have great potential for developing artificial photonic synapses which can merge data transmission and storage. They are highly desired for next generation neuromorphic computing. The recent progress of perovskite photodetectors and their application in artificial photonic synapses are summarized in this review. Firstly, the key performance parameters of photodetectors are briefly introduced. Secondly, the recent research progress of photodetectors including photoconductors, photodiodes, and phototransistors is summarized. Finally, the applications of perovskite photodetectors in artificial photonic synapses in recent years are highlighted. All these demonstrate the great potential of perovskite photonic synapses for the development of artificial intelligence. [ABSTRACT FROM AUTHOR]

Polymer semiconductors with coplanar, π-extended confirmation and high electron affinity are regarded as the promising candidates for high-mobility ambipolar organic field-effect transistors. Herein a highly electron-deficient, coplanar, π-extended bis-pyridal[2,1,3]thiadiazole (BPT) acceptor is embedded into two novel D–A type conjugated polymers (PBPT-TT and PBPT-FTT), in which alkyl-substituted terthiophenes (TT) and alkyl-substituted difluoroterthiophenes (FTT) are used as the donor segments, respectively. Moreover, a facile fluorination strategy is adopted to regulate the backbone coplanarity, optoelectrical properties, and film organization coupled with the charge transport properties of polymers. It is found that, compared with PBPT-TT, the attachment of electron-deficient fluorine substituents to the main chain of PBPT-FTT achieves not only improved electron affinity, but also enhanced backbone coplanarity owing to the formation of the F⋯S noncovalent conformation lock. Such good backbone coplanarity and fluorine substituents endow PBPT-FTT with improved interchain organization ability, thereby achieving a more uniform lamellar structure and a smaller π–π stacking distance than those of PBPT-TT. Benefiting from these merits, PBPT-FTT based organic field-effect transistors exhibit significantly improved ambipolar transport performance relative to PBPT-TT. The highest hole (μh) and electron (μe) mobilities of PBPT-FTT are determined to be 0.332 and 1.602 cm2 V−1 s−1, respectively; both of them are much higher than those of PBPT-TT (μh/μe = 0.0135/0.0191 cm2 V−1 s−1). Our findings suggest that the introduction of accessible fluorine substituents in the polymer main chain is a feasible and effective pathway to enhance the backbone coplanarity, film organization, and charge transport ability. [ABSTRACT FROM AUTHOR]

The increasing use of pesticides has raised concerns about the risks of exposure to pesticides. Rapid, simple and sensitive detection of pesticides is still a challenge in the current analytical technology. Herein, a perfluorinated copper phthalocyanine (F16CuPc) organic field-effect transistor (OFET) modified by β-cyclodextrin (β-CD) was used to detect boscalid molecules in solution. As a molecular carrier, β-CD will capture boscalid to form an inclusion complex. The hydroxyl group in β-CD and the carbonyl group in boscalid form a dipole–dipole interaction with F16CuPc, which induces more carriers in the device channel, which finally manifests as a significant increase in the maximum current of the device. When using β-CD as the modification layer, the detection limit of the device can be as low as 2.40 × 10−11 g L−1, which is 5 orders of magnitude lower than the internationally permitted MRL value. [ABSTRACT FROM AUTHOR]

Quinoidal bithiophene (QBT) is a highly attractive building block for high-performance polymeric semiconductors. However, it is a challenge to prepare a single regioisomer of a QBT-based building block using an indophenine reaction. Here, we introduce steric hindrance of the methoxyl group in a QBT-based system, which ensures the stereospecificity of the resulting monomers. Both methoxylated QBT (MQBT) and fluorinated MQBT (2FMQBT) monomers are copolymerized with 2,2′-bithiophene and 3,3′-difluoro-(2,2′-bithiophene) (DFBT) to form four donor–acceptor (D–A) copolymers, which display a narrow optical bandgap (<1.20 eV). Because of the introduction of fluorine atoms, P2FMQBT-DFBT displays good coplanarity and close solid-state packing, possessing the highest hole mobility of up to 2.70 cm2 V−1 s−1, which represents one of the best values for quinoidal polymers. Most importantly, the preparation of single regioisomers of MQBT and 2FMQBT is synthetically feasible for creating new QBT-based high-performance polymers. [ABSTRACT FROM AUTHOR]

Catalytic oxidation plays a key role in transforming gaseous benzene into harmless matter, in which it is essential to look for a low-cost, environmentally friendly and efficient green catalyst/support. Herein, Ag nanoparticle (Ag NP) loaded-eggshell catalysts were successfully synthesized by a simple impregnation method, in which waste eggshells were used as an efficient template and catalyst support. SEM, XRD and ICP-OES results show that a different number of Ag NPs are uniformly distributed on the surface of eggshells, which are defined as Ag1/eggshell (10.8%), Ag2/eggshell (19.9%) and Ag3/eggshell (34.3%) catalysts according to the amounts of loaded Ag NPs. Then, the activity between the three catalysts and the pure Ag NPs was assessed based on the catalytic oxidation of benzene. Our results show that the Ag NP loaded-eggshell catalysts exhibit superior catalytic activity compared with the pure Ag NPs. Considering the balance between the cost and catalytic performance, the Ag2/eggshell catalyst was selected as the optimum research object in the subsequent work. The Ag2/eggshell catalyst calcined at 500 °C exhibited excellent catalytic activity, which is assigned to the unique channel structure of eggshell, good low-temperature reducibility, and high dispersion of particles (sizes effects) on the surface of eggshell as well as the synergetic interaction between the Ag NPs and eggshell. Furthermore, the Ag2/eggshell catalyst exhibited predominant stability even after 200 h of on-stream reaction. The reaction mechanism is put forward based on the in situ FTIR experimental results, in which some carboxylate intermediate species are confirmed. Accordingly, the waste eggshell is considered as a promising supporting material for the large-scale synthesis of noble metal catalyst with high catalytic performance and stability for VOC oxidation. [ABSTRACT FROM AUTHOR]

We report a new method to reveal the underlying scratches that are usually unseen under optical microscopy on SiC wafers after chemo-mechanical polishing (CMP) treatment. After scanning Si terminated surfaces using a picosecond pulsed laser (355 nm) for a short duration, the scratches are clearly revealed under an optical microscope. The damage thresholds by the picosecond pulsed laser are obtained for 4H- and 6H-SiC. We demonstrate that this method is equally effective in unravelling these underlying scratches as other existing state-of-art methods including those etched by molten KOH at about 400–500 °C. The method is quick, facile, less-destructive and sensitive in characterizing the underlying surface scratches. It has great potential to find practical application in quality control for SiC wafers. [ABSTRACT FROM AUTHOR]

A novel bisthiophene-fused diketopyrrolopyrrole unit (4,11-bis(2-octyldodecyl)-7H,14H-thieno[3′,2′:7,8]indolizino[2,1-a]thieno[3,2-g]indolizine-7,14-dione, BTI) has been designed as an electron acceptor and used to copolymerize with thiophene and bithiophene as electron donors to construct two D–A conjugated polymers, P1 and P2via Stille coupling, respectively. The two polymers showed excellent thermal stability, broad light absorption and a narrow energy band gap. P1 and P2 were used to fabricate organic field-effect transistors (OFETs) to evaluate their charge transport characteristics. P2 showed much better hole transport performance with a mobility of 0.1 cm2 V−1 s−1. Near-infrared (NIR) phototransistors were also fabricated by using the two polymers blended with PC71BM as the active layer. With illumination of 35 μW cm−2 at a wavelength of 850 nm, the photocurrent/dark-current ratio (P) and photoresponsivity (R) of the phototransistor based on P1/PC71BM were 3.6 × 104 and 270 A W−1, respectively. For P2/PC71BM, P was 2.5 × 104 and R reached 2420 A W−1. [ABSTRACT FROM AUTHOR]

A strongly electron-withdrawing benzo[c][1,2,5]oxadiazole (BOZ) unit, as the second electron acceptor segment, is incorporated into the naphthalenediimide (NDI) based polymer backbone for the first time. Therefore, a unipolar n-type polymer semiconductor (PNBO) with a regioregular A1–D–A2–D configuration is developed successfully. It is found that BOZ-containing polymer PNBO not only has a deep-lying LUMO energy level of ca.−4.0 eV, which facilitates electron-injection from an Au electrode into the active layer, but also possesses a deep enough low HOMO energy level of −5.9 eV for blocking hole-injection. The carrier transporting performance of PNBO is characterized by solution-processable polymeric field-effect transistors (PFETs). These results demonstrate that a smooth surface morphology and a compact solid stacking endow PNBO with excellent unipolar n-type electron-transporting characteristics; a highest electron mobility of up to 2.43 cm2 V−1 and an excellent shelf storage with a negligible decay in 70 days are achieved. [ABSTRACT FROM AUTHOR]

n-Type doping of a semi-conducting polymer used as an electron-transporting layer in a perovskite solar cell doubles the performance of the device from 6.5% to 13.93% power-conversion efficiency. This provides a new opportunity for studying various electron transporting polymers in perovskite solar cells. The doped polymer film improves electron extraction from the photoexcited perovskite and the subsequent transport of electrons. [ABSTRACT FROM AUTHOR]

Significant enhancement in the power conversion efficiency of an organic-inorganic hybrid solar cell was achieved by the use of suitably doped poly(3-hexylthiophene-2,5-diyl) (P3HT) spin coated on a 99.5% void-free perovskite layer prepared on a TiOx electron-transporting layer. The 9.2% device efficiency with pristine P3HT was increased to 12.4%. [ABSTRACT FROM AUTHOR]

High-performance organic phototransistors (OPTs) have been successfully constructed using bitriisopropylsilylethynyl tetraceno[2,3-b]thiophenes (TIPSEthiotet) or pentacene as a semiconductor layer. Fluorographene (FG) nanosheets were used to modify the interface between an organic semiconductor layer and gate dielectric. The effects of interface modification were investigated. It was found that enhanced photoresponsivity and a boosted photocurrent/dark-current ratio could be easily achieved after the implantation of modification layers. The constructed FG-modified devices based on TIPSEthiotet showed a maximum photoresponsivity of 21.83 A W−1 and a photocurrent/dark-current ratio of 1.85 × 106 under white light irradiation. Meanwhile, for the FG-modified OPT device based on pentacene, a high photoresponsivity of 144 A W−1 was obtained under white light irradiation with an optical power of as low as 25 μW cm−2. This photoresponsivity datum is higher than that of most OPTs based on pentacene reported under the same conditions. In addition, the mobilities of the devices could also be increased distinctly after the introduction of the FG-modified layer. The experimental facts indicate that the strong electron trapping ability of the fluorine atoms in the FG nanosheets and the well-known photovoltaic effect play an important role in these interesting results. [ABSTRACT FROM AUTHOR]

As the youngest in the graphene family, fluorographene has received numerous expectations from the scientific community. Investigation of fluorographene is similar to graphene and graphene oxide, wherein fabrication is an importance subject in the infancy stage. Fluorographene produced by the currently existing protocols, however, could only disperse in a limited number of solvents, and the dispersions generally exhibit short-term stability, restricting its manipulation and processing. To address this formidable challenge, we herein report that fluorographene nanosheets, most of which have a single-layered structure, could be easily formulated from commercially available graphite fluoride via a one-pot chloroform-mediated sonochemical exfoliation under ambient conditions without any pretreatment, special protection or stabilizers. Significantly, owing to the exceptional volatility of chloroform, our fluorographene originally dispersed in chloroform, could be facilely transferred into other 24 kinds of solvents via a volatilization–redispersion process, wherein dispersions of extremely long-term stability (more than six months) could be obtained. As an example to demonstrate the merit of the as-formulated fluorographene and its potential application possibilities, we further show that our fluorographene could be easily assembled as a modified layer in pentacene-based organic field-effect transistors simply by a spin-coating method, wherein distinctly increased mobility and positively shifted threshold voltage could be achieved. Considering the excellent popularity of chloroform in the scientific community, the remarkable volatility of chloroform, the broad solvent dispersibility of our fluorographene, and together with the long-term stability of the dispersions, our chloroform-mediated sonochemical exfoliation protocol likely endow fluorographene with new and broad opportunities for fabrication of graphene-based advanced functional films and nanocomposites via liquid-phase manipulation or solution-processing strategies. [ABSTRACT FROM AUTHOR]

Among the reported organic n-type semiconductors naphthalene diimide (NDI) derivatives have received more and more attention. In this paper, we report two sulfur-rich expanded NDI derivatives 1and 2containing 1,3-dithiole-2-thione-4,5-dithiolate and 1,3-dithiole-2-one-4,5-dithiolate units, respectively. Electrochemical, absorption, spectral and theoretical calculation studies show that LUMO energies of 1and 2are lower than that of a typical NDI without functional substitution. OFET devices based on thin-films of 1and 2which can be easily solution-processed are fabricated with conventional techniques. The performance of OFET devices of 1and 2can be significantly improved by fast annealing (about 30 s) their thin-films in air, with high on/off ratios (106–107) and relatively high electron mobilities of up to 0.05 and 0.04 cm2V−1s−1, respectively. [ABSTRACT FROM AUTHOR]

We report stable organic field-effect transistors (OFETs) based on pentacene. It was found that device stability strongly depends on the dielectric layer. Pentacene thin-film transistors based on the bare or polystyrene-modified SiO2gate dielectrics exhibit excellent electrical stabilities. In contrast, the devices with the octadecyltrichlorosilane (OTS)-treated SiO2dielectric layer showed the worst stabilities. The effects of the different dielectrics on the device stabilities were investigated. We found that the surface energy of the gate dielectric plays a crucial role in determining the stability of the pentacene thin film, device performance and degradation of electrical properties. Pentacene aggregation, phase transfer and film morphology are also important factors that influence the device stability of pentacene devices. As a result of the surface energy mismatch between the dielectric layer and organic semiconductor, the electronic performance was degraded. Moreover, when pentacene was deposited on the OTS-treated SiO2dielectric layer with very low surface energy, pentacene aggregation occurred and resulted in a dramatic decrease of device performance. These results demonstrated that the stable OFETs could be obtained by using pentacene as a semiconductor layer. [ABSTRACT FROM AUTHOR]

Two novel C60fullerene derivatives containing one or two perfluorooctyl groups were designed and efficiently synthesized. Organic field-effect transistors based on the bisperfluorooctyl compound 1show high mobility up to 6.7 × 10−2cm2V−1s and high on/off ratio up to 5 × 107, which qualifies compound 1as promising n-type conductor material. [ABSTRACT FROM AUTHOR]

Correction for 'Perovskite photodetectors and their application in artificial photonic synapses' by Xin Huang et al., Chem. Commun., 2021, DOI: 10.1039/d1cc04447h. [ABSTRACT FROM AUTHOR]

A facile one-step Stöber route to synthesize high-quality core–shell–shell templates is reported for the fabrication of Au@carbon yolk–shell nanostructures. The converted Au@carbon yolk–shell nanostructures exhibited high catalytic performance as illustrated by the reduction reaction of o-nitrophenol. [ABSTRACT FROM AUTHOR]

Swift fabrication of a non-covalently modified reduced graphene oxide electronic sensor has been developed. An unparalleled detection limit is demonstrated for Hg2+, down to the picomolar range. [ABSTRACT FROM AUTHOR]

A diketopyrrolopyrrole–thiazolothiazole copolymer with a short π–π stacking distance (3.52 Å), due to the introduction of heteroaromatic rings, exhibits a high charge mobility above 3.40 cm2 V−1 s−1 at a relatively gentle annealing temperature. [ABSTRACT FROM AUTHOR]

Two linear fused heteroacenes bearing a pyrrolo[3,2-b]pyrrole core have been synthesized via a novel reductive ring closure methodology in three steps and in good overall yield. Preliminary OFET results showed that dinaphtho[2,3-b:2',3'-f]pyrrolo[3,2-b]pyrrole (DNPP) is a potential candidate for organic electronics.

A simple nickel bis(dithiolene) complex has been developed as an excellent n-type molecular semiconductor for FETs, with an electron mobility of 0.11 cm(2) V(-1) s(-1) and an on/off ratio of 2 × 10(6) despite its small π-conjugated system. Good FET stability in ambient conditions has also been observed.

A fused-seven-ring anthracene derivative with two sulfur bridges, benzobisthioxanthene (BTA), was synthesized, facilely. OLEDs employing BTA as the emitter exhibited bright (maximum 40,752 cd m(-2)) and efficient red emission (CIE, x = 0.64, y = 0.36) with a luminous efficiency of 4.4 cd A(-1).

Large-flake graphene membranes up to 300 microm(2) can be exfoliated from graphite by oleyl amine based on solvothermal conditions. The exfoliated graphene sheets are of high quality and have few defects. The graphene dispersion, predominantly composed of monolayer graphene, had a high concentration of 0.15 mg ml(-1), and can be stabilized against re-aggregation.

A new thienoacene with a sulfur-rich fused-nine-ring core was synthesized; bulk quantities of nanoribbons with mobilities as high as 0.42 cm(2) V(-1) s(-1) were obtained by a direct solution process under ambient conditions.

A novel type of anti and syn isomers of a pentacyclic compound consisting of two thiophene rings and one pyrrole ring were efficiently synthesized from benzo[b]thiophene, and the anti isomer exhibits better charge transport and OFET properties compared with the syn isomer and its N-hexyl substitution.

We report high performance organic field-effect transistors (OFETs) with the modified Cu bottom-contact electrodes. Efficient modification of the Cu electrodes with nanometer-size copper tetracyanoquinodimethane (Cu-TCNQ) increases the electrode/organic layer contact area and reduces contact resistance. We investigated the effect of the Cu-TCNQ morphology on the device performance. The pentacene-based OFETs with the modified Cu bottom-contact electrodes exhibited high device performance. The field-effect mobility up to 0.31 cm(2)/V s was achieved. To the best of our knowledge, this is the highest device performance for the OFETs with the bottom Cu electrodes ever reported. Consequently, our results provide an effective approach to fabricate high performance and low-cost OFETs.