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A robust hole transporting layer (HTL), using the cost‐effective Cobalt(II) acetate tetrahydrate (Co(OAc)2⋅4 H2O) as the precursor, was simply processed from its aqueous solution followed by thermal annealing (TA) and UV‐ozone (UVO) treatments. The TA treatment induced the loss of crystal water followed by oxidization of Co(OAc)2⋅4 H2O precursor, which increased the work function. However, TA treatment differently realize a high work function and ideal morphology for charge extraction. The resulting problems could be circumvented easily by additional UVO treatment, which also enhanced the conductivity and lowered the resistance for charge transport. The optimal condition was found to be a low temperature TA (150 °C) followed by simple UVO, where the crystal water in Co(OAc)2⋅4 H2O was removed fully and the HTL surface was anchored by substantial hydroxy groups. Using PM6 as the polymer donor and L8‐BO as the electron acceptor, a record high PCE of 18.77 % of the binary blend OSCs was achieved, higher than the common PEDOT:PSS‐based solar cell devices (18.02 %). [ABSTRACT FROM AUTHOR]

A robust hole transporting layer (HTL), using the cost‐effective Cobalt(II) acetate tetrahydrate (Co(OAc)2⋅4 H2O) as the precursor, was simply processed from its aqueous solution followed by thermal annealing (TA) and UV‐ozone (UVO) treatments. The TA treatment induced the loss of crystal water followed by oxidization of Co(OAc)2⋅4 H2O precursor, which increased the work function. However, TA treatment differently realize a high work function and ideal morphology for charge extraction. The resulting problems could be circumvented easily by additional UVO treatment, which also enhanced the conductivity and lowered the resistance for charge transport. The optimal condition was found to be a low temperature TA (150 °C) followed by simple UVO, where the crystal water in Co(OAc)2⋅4 H2O was removed fully and the HTL surface was anchored by substantial hydroxy groups. Using PM6 as the polymer donor and L8‐BO as the electron acceptor, a record high PCE of 18.77 % of the binary blend OSCs was achieved, higher than the common PEDOT:PSS‐based solar cell devices (18.02 %). [ABSTRACT FROM AUTHOR]

The molecular planarity of a small molecule donor is one of the key factors affecting its molecular packing behavior, the morphology of the related active blend and thus the photovoltaic properties of all small molecule organic solar cells (ASM-OSCs). In this contribution, a series of new benzodithiophene (BDT)-based A-π-D-π-A type small molecules were developed, namely SD1, SD2 and SD3, by combining the chemical modification of side chain (sulfuration), π-bridge (alkoxy groups introducing) and end group (different type or different alkyl chain). The sulfuration of the BDT side chains and introducing alkoxy group to the π-bridge could induce intermolecular S⋯S and intramolecular S⋯O non-covalent interactions for higher planarity of these small molecules. The rhodanine and cyanoacetate end groups showed less effect on the optical and electronic properties but significantly affected the molecular packing behavior and blend morphology. From SD1:Y6-T to SD2:Y6-T and SD3:Y6-T, the face-to-face packing was gradually reduced, while the face-to-edge packing was increased, which resulted in lowered exciton dissociation efficiency, further decreased the device performance. SD1:Y6-T blend exhibited more favorable face-to-face packing and ideal morphology for efficient charge dissociation and transport, contributing to a champion PCE of 10.12%. This work provided a deep insight of the donor and acceptor packing behavior effect on the photovoltaic property by molecular design. [Display omitted] [ABSTRACT FROM AUTHOR]

The working horses for the drastically improved power conversion efficiency (PCE) of organic solar cells (OSCs) were the small-band-gap molecular non-fullerene acceptors. This development not only removed the low performance obstacle for OSCs but also raised needs for wide-band-gap polymers for donor/acceptor mix with complimentary absorptions. Benzodithiophene (BDT) is one of the mostly used unit for constructing donor polymers. Here, we introduced one type of donor polymer with two BDT units placed perpendicularly. This exploration is aimed to reduce the complexity of molecule design, potentially to reduce the cost of donor materials. We also explored the halogenation of BDT side group to optimize the performances of the copolymers. The chlorinated donor polymer PvBDT-Cl delivered a decent PCE of 8.23% with Y6-T. This work explored the possibility of using only BDT unit to construct high performance donor polymers, which is a crucial insight for future low-cost donor polymer design. [Display omitted] • Wide-band-gap polymers were developed with BDT placed perpendicularly for OSCs. • Halogenation was used to fine tune energetic structures and inherent properties. • Chlorinated PvBDT-Cl devices delivered higher PCE than fluorinated counterpart. [ABSTRACT FROM AUTHOR]

Organic solar cells incorporating non‐fullerene acceptors (NFAs) have reached remarkable power conversion efficiencies of over 18%. Unlike fullerene derivatives, NFAs tend to crystallize from solutions, resulting in bulk heterojunctions that include a crystalline acceptor phase. This must be considered in any morphology‐function models. Here, it is confirmed that high‐performing solution‐processed indacenodithienothiophene‐based NFAs, i.e., ITIC and its derivatives ITIC‐M, ITIC‐2F, and ITIC‐Th, exhibit at least two crystalline forms. In addition to highly ordered polymorphs that form at high temperatures, NFAs arrange into a low‐temperature metastable phase that is readily promoted via solution processing and leads to the highest device efficiencies. Intriguingly, the low‐temperature forms seem to feature a continuous network that favors charge transport despite of a poorly order along the π–π stacking direction. As the optical absorption of the structurally more disordered low‐temperature phase can surpass that of the more ordered polymorphs while displaying comparable—or even higher—charge transport properties, it is argued that such a packing structure is an important feature for reaching highest device efficiencies, thus, providing guidelines for future materials design and crystal engineering activities. [ABSTRACT FROM AUTHOR]

In this work, the properties and performance of three structurally similar non‐fullerene acceptors (named BTP‐Ph, BTP‐Th, and BTP‐C11) possessing different side chains on the β‐positions of the thienothiophene units of the Y6 molecule are systematically studied. The steric and electronic effects of these side chains on the blend morphology and device performance based on the PTQ10 donor polymer are investigated. It is found that the thiophene and benzene units on the side chains introduce more steric hindrance and thus slightly reduce the crystallinity of the molecule. However, an interesting matching trend with the PTQ10 donor that appears to better match with the less crystalline molecules is observed. Overall, PTQ10:BTP‐Ph delivers the highest performance of 17.1% due to the suitable phase separation among three blends. Next, a ternary strategy is explored by incorporating BTP‐Th/BTP‐C11 with better molecular packing into PTQ10:BTP‐Ph, which successfully extends photon response, enhances charge transport, and suppresses charge recombination compared with the binary blend. Due to these synergistic effects, the ternary device based on PTQ10:BTP‐Ph:BTP‐Th achieves an outstanding power conversion efficiency of 17.6% with a fill factor of 78.8%, which is the highest value of PTQ10‐based devices to date. [ABSTRACT FROM AUTHOR]

Y-type non-fullerene acceptors with outer bulky branched side chains and weaker electron withdrawing end groups were designed for polymer solar cells. A decent PCE of 15.03% was achieved for D18:BTP-TCl binary device, which was further improved to 19.15% by adding BTP-TCl to the D18:BTP-eC9 host blend. [Display omitted] • Y-typed small molecular acceptors were synthesized with upshifted LUMO levels. • D18:BTP-TCl achieved a decent PCE of 15.03 % with a high V oc of 0.986 V. • The ternary device of D18:BTP-eC9:BTP-TCl achieved a champion PCE of 19.15%. • Simultaneous enhancement of J sc and V oc of PSCs was achieved. Simultaneously enhancing the short-circuit current density (J sc) and open-circuit voltage (V oc) of current state-of-the-art polymer solar cells (PSCs) containing wide bandgap polymers as donors and Y6 derivatives as acceptors is of great challenge but essential for further improvement of the photovoltaic performances. In this work, two Y-type non-fullerene acceptors of BTP-T and BTP-TCl were designed and successfully synthesized with relatively weak electron-accepting thiophene based end groups, where blue-shifted absorption and upshifted LUMO energy levels were achieved to fill the well-known absorption gap at 700 nm of typical binary devices based Y-type molecules and rise the output voltage, respectively. Simultaneously increased J sc and V oc were achieved in ternary blend devices containing D18:BTP-eC9:BTP-TCl with a significantly improved PCE up to 19.15 %, which is over 7 % increase compared to the binary device. Our results illustrated the great potential of rational design of Y6 derivatives for constructing ternary PSCs to improve their performances. [ABSTRACT FROM AUTHOR]

While photovoltaic blends based on non‐fullerene acceptors are touted for their thermal stability, this type of acceptor tends to crystallize, which can result in a gradual decrease in photovoltaic performance and affects the reproducibility of the devices. Two halogenated indacenodithienothiophene‐based acceptors that readily co‐crystallize upon mixing are studied, which indicates that the use of an acceptor mixture alone does not guarantee the formation of a disordered mixture. The addition of the donor polymer to the acceptor mixture readily suppresses the crystallization, which results in a fine‐grained ternary blend with nanometer‐sized domains that do not coarsen due to a high Tg ≈ 200 °C. As a result, annealing at temperatures of up to 170 °C does not markedly affect the photovoltaic performance of ternary devices, in contrast to binary devices that suffer from acceptor crystallization in the active layer. The results indicate that the ternary approach enables the use of high‐temperature processing protocols, which are needed for upscaling and high‐throughput fabrication of organic solar cells. Further, ternary devices display a stable photovoltaic performance at 130 °C for at least 205 h, which indicates that the use of acceptor mixtures allows to fabricate devices with excellent thermal stability. [ABSTRACT FROM AUTHOR]

The development of small molecule-based non-fullerene acceptors (NF-SMAs) greatly advanced the performances of polymer solar cells (PSCs) in recent years. As the foreseeability of commercializing this technology in the future, interest in reducing the materials cost is rising. To this end, efforts have been made in this work on exploring the usage of commercially available chemical segment of benzothiophene dioxide (BC) in constructing efficient NF-SMAs. Thus, we designed and synthesized two BC-based NF-SMAs, which showed high power conversion efficiency (PCE) of 7.59% also by device engineering and side chain engineering. Our work revealed the full potential of using BC end groups in constructing high-performance NF-SMAs and demonstrated the application of side chain engineering in tuning material properties and performances. The photovoltaic potential and fundamental limitations of commercial dye based on benzothiophene dioxide (BC) as end group for constructing non-fullerene acceptors has been fully revealed through device optimization and side chain engineering. Image 1 ● An uncommon end group of benzothiophene dioxide was used to develop non-fullerene small molecule acceptors. ● Side chain effect was observed to enhance the photovoltaic performance of benzothiophene dioxide-based small molecule acceptors. ● Selecting PM6 as the donor polymer, highest PCE of 7.59% was achieved. [ABSTRACT FROM AUTHOR]

Organic blend thin films consisting of semiconducting poly(3-hexylthiophene) (P3HT) and insulating high-density polyethylene (HDPE) have been fabricated by novel application of a large area wire-bar coating technique in air. The microstructure of P3HT:HDPE blend films reveals a strong structural dependence on initial composition. Preferential segregation of P3HT toward the film surface is observed for all blend compositions, while P3HT (or P3HT-rich) columnar structures enclosed by HDPE (or HDPE-rich) lamellar matrix is distinctive for 50:50 (by weight) blends. The transistors fabricated with P3HT:HDPE blend films show a clear field effect behavior, exhibiting charge carrier mobilities up to 5 × 10-2 cm2/Vs, comparable to the values reported in spin-coated similar blends and of neat P3HT devices. The wire-bar coated blend films and devices are highly repeatable and spatially uniform over large areas (few cm by few cm), demonstrating the suitability of this technique for manufacturing of large area organic electronic devices. [ABSTRACT FROM AUTHOR]

Background: Patients with gallstone pancreatitis (GP) or choledocholithiasis (CDL) may have common bile duct (CBD) stones that persist until cholangiography. The aim of this study is to evaluate pre-cholangiogram factors that predict persistent CBD stones.Methods: Multiple logistic regression analyses were performed to identify demographic, laboratory, and radiologic predictors of persistent CBD stones and non-therapeutic cholangiography among adults with GP or CDL.Results: In 152 patients from 2010 to 2015, preoperative diagnosis, presence of a CBD stone on US, and age ≥ 60 years were associated with persistent CBD stones. Two risk factors alone had a PPV of 88% and the absence of all risk factors had a NPV of 94%. Age < 60 years and the absence of a CBD stone on US were most predictive of non-therapeutic cholangiography.Conclusion: Age, LFTs, and US help predict persistent CBD stones in patients initially presenting with GP or CDL and help minimize non-therapeutic preoperative cholangiography. [ABSTRACT FROM AUTHOR]

Intracellular products (e.g., insulin), which are obtained through cell lysis, take up a big share of the biotech industry. It is often time-consuming, laborious, and environment-unfriendly to disrupt bacterial cells with traditional methods. In this study, we developed a molecular device for controlling cell lysis with light. We showed that intracellular expression of a single lysin protein was sufficient for efficient bacterial cell lysis. By placing the lysin-encoding gene under the control of an improved light-controlled system, we successfully controlled cell lysis by switching on/off light: OD600 of the Escherichia coli cell culture was decreased by twofold when the light-controlled system was activated under dark condition. We anticipate that our work would not only pave the way for cell lysis through a convenient biological way in fermentation industry, but also provide a paradigm for applying the light-controlled system in other fields of biotech industry. [ABSTRACT FROM AUTHOR]

Foaming of plastics allows for extensive tuning of mechanical and physicochemical properties. Utilizing the foam architecture for plastic semiconductors can be used to improve ingression of external molecular species that govern the operation of organic electronic devices. In case of plastic thermoelectrics, utilizing solid semiconductors with realistic (millimeter (mm)-thick) dimensions does not permit sequential doping-while sequential doping offers the higher thermoelectric performance compared to other methods-because this doping methodology is diffusion limited. In this work, a fabrication process for poly(3-hexylthiophene) (P3HT) foams is presented, based on a combination of salt leaching and thermally induced phase separation. The obtained micro- and nanoporous architecture permits rapid and uniform doping of mm-thick foams with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, while thick solid P3HT structures suffer from protracted doping times and a dopant-depleted central region. Importantly, the thermoelectric performance of a P3HT foam is largely retained when normalized with regard to the quantity of used material. [ABSTRACT FROM AUTHOR]

Children residing in urban, low-resource neighborhoods may be at increased risk for poor aerobic fitness and obesity. The objective of this collaborative project with an urban public school district was to quantify the combination of poor aerobic capacity and high percent body fat using FITNESSGRAM® Healthy Fitness Zone (HFZ) standards among urban, predominantly Black, public elementary school boys and girls. Measurements of aerobic capacity with the 20-m Progressive Aerobic Cardiovascular Endurance Run (PACER) test and body composition by bioelectrical impedance analysis were completed on 1,775 fourth and fifth grade students in 45 public elementary schools in St. Louis, Missouri during three school years (2012-2015). Our findings reveal that a higher proportion of girls than boys failed to meet the HFZ for aerobic capacity (70.1% vs. 42.3%), percent body fat (53.0% vs. 29.9%), and the combination of aerobic capacity and percent body fat (44.4% vs. 21.8%, all P<0.001). These results highlight the importance of addressing modifiable, lifestyle-related health risks among urban minority children, particularly girls. [ABSTRACT FROM AUTHOR]

In organic solar cells (OSCs), the energy of the charge-transfer (CT) complexes at the donor-acceptor interface, ECT, determines the maximum open-circuit voltage ( VOC). The coexistence of phases with different degrees of order in the donor or the acceptor, as in blends of semi-crystalline donors and fullerenes in bulk heterojunction layers, influences the distribution of CT states and the VOC enormously. Yet, the question of how structural heterogeneities alter CT states and the VOC is seldom addressed systematically. In this work, we combine experimental measurements of vacuum-deposited rubrene/C60 bilayer OSCs, with varying microstructure and texture, with density functional theory calculations to determine how relative molecular orientations and extents of structural order influence ECT and VOC. We find that varying the microstructure of rubrene gives rise to CT bands with varying energies. The CT band that originates from crystalline rubrene lies up to ≈0.4 eV lower in energy compared to the one that arises from amorphous rubrene. These low-lying CT states contribute strongly to VOC losses and result mainly from hole delocalization in aggregated rubrene. This work points to the importance of realizing interfacial structural control that prevents the formation of low ECT configurations and maximizes VOC. [ABSTRACT FROM AUTHOR]

Humidity is a vital physical quantity which is extremely important to production quality control, reliability of electronics, and health of human being. This paper proposed a humidity sensor based on quartz crystal microbalance (QCM) using graphene oxide as a sensitive layer, and investigated the characteristics of sensor according to the shift of quality factor (Q factor) as well as resonant frequency at different relative humidity (RH). Results show that at low RH values, the shift of Q factor is more suitable than the shift of resonant frequency for assessing the sensitivity of the sensor. By combining both frequency and Q factor shifts, we obtain a sensitivity of ∼1371/1%RH at 10–60%RH (by Q factor) and 1068 Hz/10%RH at 70%RH (by frequency), which are much better than the reported QCM humidity sensors, with good linearity. The QCM humidity sensor also shows good repeatability with response time and recovery time smaller than 20 and 3 s, respectively. These good characteristics of the sensor are attributed to the large surface area and high hydrophilic nature of the graphene oxide, demonstrated good potential for future applications. [ABSTRACT FROM AUTHOR]

The random ternary copolymerization of BDD and DTBT segments to develop random terpolymers finely tuned absorptions, energy levels and molecular crystallinity. The optimized blend morphology also enabled fast exciton diffusion and dissociation, efficient charge extraction with suppressed recombination, thus improving the power conversion efficiency from 17.22% to 18.12% of the related organic solar cells. The terpolymer also exhibited improved batch-to-batch productivity than the control PM6 and D18 donors. [Display omitted] • Random terpolymers were developed by combining the PM6 and D18 segments. • The structure–property relationship of these random terpolymers was systematically investigated. • The optimal terpolymer PMD-15 improved the PCE from 17.22% to 18.12%. Developing high-performance wide bandgap polymer donors to match the rapidly growing non-fullerene small molecule acceptors (NF-SMAs) is of great importance to further improve the photovoltaic performances of organic solar cells (OSCs). PM6 and D18 are two leading wide bandgap donor polymers, but their performances are highly sensitive to the molecular weights, which have distinct impact on the morphology and thereby the charge generation and recombination processes. In this work, we reported the random ternary copolymerization of PM6 and D18 segments to develop random terpolymers with finely tuned photoelectronic properties and optimized blend morphology for high-performance OSCs. The resulting random terpolymers (PMD-5, PMD-10, PMD-15 and PMD-20) exhibited finely tuned absorptions, energy levels and blend morphology. The optimal morphology of PMD-15:L8-BO contributed to the fast exciton diffusion and dissociation, efficient charge extraction with suppressed recombination. Thus, the power conversion efficiency was improved from 17.22% of the control PM6 devices and 17.47% of the control D18 devices to 18.12% of PMD-15 based devices, which is the top performance of random terpolymers. Moreover, the PMD-15 exhibited much higher batch-to-batch reproducibility at a broad molecular weight range than that of PM6 and D18, showing promising for practical applications. [ABSTRACT FROM AUTHOR]

Thermoelectric plastics are a class of polymer-based materials that combine the ability to directly convert heat to electricity, and vice versa, with ease of processing. Potential applications include waste heat recovery, spot cooling and miniature power sources for autonomous electronics. Recent progress has led to surging interest in organic thermoelectrics. This tutorial review discusses the current trends in the field with regard to the four main building blocks of thermoelectric plastics: (1) organic semiconductors and in particular conjugated polymers, (2) dopants and counterions, (3) insulating polymers, and (4) conductive fillers. The design and synthesis of conjugated polymers that promise to show good thermoelectric properties are explored, followed by an overview of relevant structure–property relationships. Doping of conjugated polymers is discussed and its interplay with processing as well as structure formation is elucidated. The use of insulating polymers as binders or matrices is proposed, which permit the adjustment of the rheological and mechanical properties of a thermoelectric plastic. Then, nanocomposites of conductive fillers such as carbon nanotubes, graphene and inorganic nanowires in a polymer matrix are introduced. A case study examines poly(3,4-ethylenedioxythiophene) (PEDOT) based materials, which up to now have shown the most promising thermoelectric performance. Finally, a discussion of the advantages provided by bulk architectures e.g. for wearable applications highlights the unique advantages that thermoelectric plastics promise to offer. [ABSTRACT FROM AUTHOR]

The combined strategies of alkoxy-side chain isomerization and conjugated skeleton asymmetry were performed to verify the structure–property-performance relationship of Y6-based small molecule acceptors, revealing X-TO1 featured with increased crystallinity, purer phase, improved electron transport mobility and thus the highest PCE of 15.63%. [Display omitted] • Structure-property-performance relationship of Y6 small molecule was investigated. • X-TO1 exhibited preferred molecular configuration and polymorph with PCE of 15.63%. • This work implied the isomerization and polymorphism for rising device performance. Non-fullerene small molecule acceptors (NF-SMAs) such as Y6 derivatives were the current working horse for the top performing polymer solar cells (PSCs). For this reason, numerous chemical modifications have been explored for establishing structure–property-performance relationship for Y6-based NF-SMAs. In this work, we explored the isomerization on asymmetrical Y6 derivatives by varying the position of alkoxy side chain on the thiophene linkage between the core and one of the end groups of Y6. The isomers with differences in conformational restriction raised by noncovalent interactions as well as steric hindrance revealed distinctive behavior in crystallization and polymorphism, which led to a significant contrast in PSC performances. The X-TO1 molecule with alkoxy side chain facing the end group (outward) displayed preferred molecular configuration and polymorph, delivering power conversion efficiency (PCE) of 15.63%, while its isomer X-TO2 showed coexisted polymorphs significantly increased the charge recombination in the PSC devices led to a low PCE around 3%. This structure–property-performance relationship not only highlighted the elegancy of isomerization in tuning the photovoltaic performances but also identified polymorphism as one of the causes for impairing photovoltaic performances of PSCs. [ABSTRACT FROM AUTHOR]

Blending of small-molecule organic semiconductors (OSCs) with amorphous polymers is known to yield high performance organic thin film transistors (OTFTs). Vertical stratification of the OSC and polymer binder into welldefined layers is crucial in such systems and their vertical order determines whether the coating is compatible with a top and/or a bottom gate OTFT configuration. Here, we investigate the formation of blends prepared via spin-coating in conditions which yield bilayer and trilayer stratifications. We use a combination of in situ experimental and computational tools to study the competing effects of formulation thermodynamics and process kinetics in mediating the final vertical stratification. It is shown that trilayer stratification (OSC/polymer/OSC) is the thermodynamically favored configuration and that formation of the buried OSC layer can be kinetically inhibited in certain conditions of spin-coating, resulting in a bilayer stack instead. The analysis reveals here that preferential loss of the OSC, combined with early aggregation of the polymer phase due to rapid drying, inhibit the formation of the buried OSC layer. The fluid dynamics and drying kinetics are then moderated during spin-coating to promote trilayer stratification with a high quality buried OSC layer which yields unusually high mobility >2 cm² V-1 s-1 in the bottom-gate top-contact configuration. [ABSTRACT FROM AUTHOR]

Y6 isomer of i -Y6 with a W-shape was explored as a vitrification agent and a solid additive for polymer solar cells, providing a significant raise to the PCE of PM6:Y6 from 16.827% to 17.433% at a dosage of Y6: i -Y6 ratio of 24:1. [Display omitted] • Y6 isomer of i -Y6 was designed with the U-shaped Y6 molecule inverted to a W-shape. • i -Y6 molecule crystallized poorly in a different packing style than Y6. • i -Y6 was explored as a vitrification agent for PM6:Y6 polymer solar cells. • i -Y6 provided a raise to the PCE of PM6:Y6 blend from 16.827% to 17.433%. The current top-performing polymer solar cell (PSC) systems are mostly based on PM6:Y6 host blend. To date, numerous materials have been explored as the third component for these systems to form ternary blends or as additives. Vitrification agents are a group of additives proved to be useful in affecting the morphology of organic semiconductors. To design a suitable vitrification agent for non-fullerene electron acceptor Y6, an isomer strategy was explored where the thienothiophene wings of the Y6 molecule were inversed to form a W-shaped Y6 isomer of i -Y6. It was found that i -Y6 crystallized poorly with a different packing style than Y6 and could blend well in amorphous phase of Y6. These properties enabled i -Y6 to finely tune the morphology of PM6:Y6 blend at low additive dosages. The power conversion efficiency (PCE) of PM6:Y6 based PSC was raised from 16.827% to 17.433% at a dosage of Y6: i -Y6 ratio of 24:1. This work demonstrated isomerization as a viable strategy for developing solid additives for high performance PSC blends and vitrification agents as effective additives for tuning morphology and improving performances of PSCs. [ABSTRACT FROM AUTHOR]

BTP-based polymer accepters with low-lying HOMO level and reduced synthesis complexity were developed for all polymer solar cells. Top PCEs of 14.32% and 16.04% were achieved in binary and ternary blends using such BTP-based polymer acceptors, even featuring a very low FOM of 3.65. [Display omitted] • BTP based polymer acceptors were designed and synthesized. • The BTP-based polymers show high performances with the lowest cost-efficiency. • The top PCE of 16.04% was obtained in ternary blend All-PSCs. All-polymer solar cells (All-PSCs) attracted increasing attention due to the outstanding thermal stability and mechanical properties. The current prevailing polymer acceptors for most efficient All-PSCs are polymerized high-performance small molecule acceptor of Y6, i.e. the dithienothiopheno[3,2-b]-pyrrolobenzothiadiazole (BTTP) based polymers. However, the BTTP-based polymers often show relatively shallow highest occupied molecular orbital (HOMO) energy level and high figure of merit (FOM), which limit the rational selection of paring donor polymers. Herein, we presented two low-cost polymer acceptors, namely as BTP-T2F and BTP-2T2F, based on lowly fused dithienopyrrolo[3,2b]benzothiadiazole (BTP, removing two thiophene cycles from BTTP). The BTP-based polymers exhibited deeper HOMO levels around −5.90 eV, which could match variable donor polymers with low-lying HOMO levels, such as low-cost PTQ10. Additionally, the synthesis was significantly simplified compared to BTTP-based polymers. A power conversion efficiency (PCE) of 14.32% was achieved in binary blend device containing PTQ10:BTP-2T2F. By adding a miscibility-enhancing PBDTCl-TPD as a third component, the top PCE of 16.04% was obtained in ternary blend All-PSCs. Combining the high device performance and low estimated cost, extraordinary cost-efficiency balance was realized within these BTP-based polymer acceptors. [ABSTRACT FROM AUTHOR]

Abstract: Electronic properties of organic semiconductors are often critically dependent upon their ability to order from the molecular level to the macro-scale, as is true for many other materials attributes of macromolecular matter such as mechanical characteristics. Therefore, understanding of the molecular assembly process and the resulting solid-state short- and long-range order is critical to further advance the field of organic electronics. Here, we will discuss the structure development as a function of molecular weight in thin films of a model conjugated polymer, poly(3-hexylthiophene) (P3HT), when processed from solution and the melt. While focus is on the microstructural manipulation and characterization, we also treat the influence of molecular arrangement and order on electronic processes such as charge transport and show, based on classical polymer science arguments, how accounting for the structural complexity of polymers can provide a basis for establishing relevant processing/structure/property-interrelationships to explain some of their electronic features. Such relationships can assist with the design of new materials and definition of processing protocols that account for the molecular length, chain rigidity and propensity to order of a given system. [Copyright &y& Elsevier]

Additives, including nucleating agents, have been used to regulate the solidification process of (semi-)crystalline polymer solids and thus control both their crystallite dimensions and shape. Here, we demonstrate that minute amounts (0.1-1 wt%) of commercially available nucleating agents can be used to efficiently manipulate the solidification kinetics of a wide range of organic semiconductors-including poly(3-alkylthiophene)s, the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and 6,13-bis(triisopropyl-silylethynyl) (TIPS) pentacene-when processed from the melt, solution or solid state, without adversely affecting the semiconductors' electronic properties. Heterogeneous nucleation increases the temperature of and rate of crystallization of poly(3-alkylthiophene)s, permits patterning of crystallites at pre-defined locations in PCBM, and minimizes dewetting of films of TIPS-pentacene formed by inkjet printing. Nucleating agents thus make possible the fabrication of thin-film transistors with uniform electrical characteristics at high yield. [ABSTRACT FROM AUTHOR]

Abstract: Blends of chemically readily accessible, small-molecular arylacetylene derivatives with poly(vinylidene fluoride) (PVDF) are presented that allow reliable solution processing of field-effect transistor (FET) architectures with electronic characteristics comparable to those of the neat semiconductors. We demonstrate that having the chemical means and corresponding processing protocols to control solid-state microstructures by either adjusting the chemical nature of the organic semiconductor, blend composition or deposition temperature, permit straight-forward comparison between materials and allow probing if electronic characteristics are affected by the chemical structure of the organic semiconductor and/or selected processing protocols. [Copyright &y& Elsevier]

Dimerization is a widely adopted approach to construct electron accepting materials for polymer solar cells (PSCs). Fullerene dimers were extensively explored with improved structural stability and perylene-diimide (PDI) dimers prevented the formation of undesired large crystals. However, dimers of indacenodithieno[3,2- b ]thiophene (IDTT) chromophores have yet not been reported despite the great success in non-fullerene small molecule acceptors (NF-SMAs) such as ITIC. In this work, we designed and synthesized three IDTT dimers with conjugated cores or not and explored the core effect of introducing flexible dithiophene or rigid thienothiophene as linkage group. All the three IDTT dimers were found to be poorly crystallized and functional PSCs devices containing each of these dimers were successfully fabricated paring with donor polymer PBDB-T. The introduction of electron donating linkages raise energy levels of the dimers hence increased the open circuit voltages. Thienothiophene was found to be a more suitable linkage unit than dithiophene but the highest power conversion efficiency of 6.01% was recorded in devices based on dimer dIDTT without the linkage units. This work demonstrated the possibility of using IDTT chromophore to construct dimer NF-SMAs and revealed insights of core effect on their photovoltaic performance. [Display omitted] • IDTT-based dimers with or without core were synthesized as NF-SMAs for PSCs. • Introduction of flexible or rigid linkages between the IDTT units were explored. • Highest PCE of 6.01% was achieved in PSC devices containing dIDTT without any core. [ABSTRACT FROM AUTHOR]

A triboelectric nanogenerator-based self-powered resonant sensor is proposed and investigated. By integrating an inductor and a microswitch with a triboelectric nanogenerator, a new type triboelectric nanogenerator is obtained, the pulse voltage output is converted to an oscillating signal with a very stable modulated resonant frequency, immune to the cross disturbance of contact-related variation (force, frequency, distance) and environmental variation, such as humidity and temperature. This is utilized for non-destructive defect detection. When the coil inductor scans the surface of a specimen with defects, varying resonant frequencies are obtained for different types of defects, showing excellent consistency between the experimental and simulated results. The results demonstrate the potential of the self-powered TENG-based resonant sensor to be a highly stable and sensitive magnetic sensor for the non-destructive defect detection applications. [ABSTRACT FROM AUTHOR]

The article discusses research on the role of a limb region 1-like gene (Lmbrl1l) mutation in regulating lymphopoiesis. Topics include the importance of endoplasmic reticulum (ER), the role of Wnt/β-catenin signaling in the hematopoietic system, and the significance of hematopoietic stem cells (HSCs).