pinecone/core-2020-05-10-deduplication huggingface dataset:
Additive manufacturing : unlocking the evolution of energy materials

The global energy infrastructure is undergoing a drastic transformation towards renewable energy, posing huge challenges on the energy materials research, development and manufacturing. Additive manufacturing has shown its promise to change the way how future energy system can be designed and delivered. It offers capability in manufacturing complex 3D structures, with near-complete design freedom and high sustainability due to minimal use of materials and toxic chemicals. Recent literatures have reported that additive manufacturing could unlock the evolution of energy materials and chemistries with unprecedented performance in the way that could never be achieved by conventional manufacturing techniques. This comprehensive review will fill the gap in communicating on recent breakthroughs in additive manufacturing for energy material and device applications. It will underpin the discoveries on what 3D functional energy structures can be created without design constraints, which bespoke energy materials could be additively manufactured with customised solutions, and how the additively manufactured devices could be integrated into energy systems. This review will also highlight emerging and important applications in energy additive manufacturing, including fuel cells, batteries, hydrogen, solar cell as well as carbon capture and storage
Remarkable Enhancement of the Hole Mobility in Several Organic Small-Molecules, Polymers, and Small-Molecule:Polymer Blend Transistors by Simple Admixing of the Lewis Acid p-Dopant B(C6F5)(3)

Improving the charge carrier mobility of solution-processable organic semiconductors is critical for the development of advanced organic thin-film transistors and their application in the emerging sector of printed electronics. Here, a simple method is reported for enhancing the hole mobility in a wide range of organic semiconductors, including small-molecules, polymers, and small-molecule:polymer blends, with the latter systems exhibiting the highest mobility. The method is simple and relies on admixing of the molecular Lewis acid B(C6F5)3 in the semiconductor formulation prior to solution deposition. Two prototypical semiconductors where B(C6F5)3 is shown to have a remarkable impact are the blends of 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene:poly(triarylamine) (diF-TESADT:PTAA) and 2,7-dioctyl[1]-benzothieno[3,2-b][1]benzothiophene:poly(indacenodithiophene-co-benzothiadiazole) (C8-BTBT:C16-IDTBT), for which hole mobilities of 8 and 11 cm2 V−1 s−1, respectively, are obtained. Doping of the 6,13-bis(triisopropylsilylethynyl)pentacene:PTAA blend with B(C6F5)3 is also shown to increase the maximum hole mobility to 3.7 cm2 V−1 s−1. Analysis of the single and multicomponent materials reveals that B(C6F5)3 plays a dual role, first acting as an efficient p-dopant, and secondly as a microstructure modifier. Semiconductors that undergo simultaneous p-doping and dopant-induced long-range crystallization are found to consistently outperform transistors based on the pristine materials. Our work underscores Lewis acid doping as a generic strategy towards high performance printed organic microelectronics
Toward Aerogel Electrodes of Superior Rate Performance in Supercapacitors through Engineered Hollow Nanoparticles of NiCo2O4

A biomass‐templated pathway is developed for scalable synthesis of NiCo2O4@carbon aerogel electrodes for supercapacitors, where NiCo2O4 hollow nanoparticles with an average outer diameter of 30–40 nm are conjoined by graphitic carbon forming a 3D aerogel structure. This kind of NiCo2O4 aerogel structure shows large specific surface area (167.8 m2 g−1), high specific capacitance (903.2 F g−1 at a current density of 1 A g−1), outstanding rate performance (96.2% capacity retention from 1 to 10 A g−1), and excellent cycling stability (nearly without capacitance loss after 3000 cycles at 10 A g−1). The unique structure of the 3D hollow aerogel synergistically contributes to the high performance. For instance, the 3D interconnected porous structure of the aerogel is beneficial for electrolyte ion diffusion and for shortening the electron transport pathways, and thus can improve the rate performance. The conductive carbon joint greatly enhances the specific capacity, and the hollow structure prohibits the volume changes during the charge–discharge process to significantly improve the cycling stability. This work represents a giant step toward the preparation of high‐performance commercial supercapacitors.Full Tex
2D Black Phosphorus: from Preparation to Applications for Electrochemical Energy Storage

Black phosphorus (BP) is rediscovered as a 2D layered material. Since its first isolation in 2014, 2D BP has triggered tremendous interest in the fields of condensed matter physics, chemistry, and materials science. Given its unique puckered monolayer geometry, 2D BP displays many unprecedented properties and is being explored for use in numerous applications. The flexibility, large surface area, and good electric conductivity of 2D BP make it a promising electrode material for electrochemical energy storage devices (EESDs). Here, the experimental and theoretical progress of 2D BP is presented on the basis of its preparation methods. The structural and physiochemical properties, air instability, passivation, and EESD applications of 2D BP are discussed systemically. Specifically, the latest research findings on utilizing 2D BP in EESDs, such as lithium‐ion batteries, supercapacitors, and emerging technologies (lithium–sulfur batteries, magnesium‐ion batteries, and sodium‐ion batteries), are summarized. On the basis of the current progress, a few personal perspectives on the existing challenges and future research directions in this developing field are provided
A micropatterned multielectrode shell for 3D spatiotemporal recording from live cells

Microelectrode arrays (MEAs) have proved to be useful tools for characterizing electrically active cells such as cardiomyocytes and neurons. While there exist a number of integrated electronic chips for recording from small populations or even single cells, they rely primarily on the interface between the cells and 2D flat electrodes. Here, an approach that utilizes residual stress‐based self‐folding to create individually addressable multielectrode interfaces that wrap around the cell in 3D and function as an electrical shell‐like recording device is described. These devices are optically transparent, allowing for simultaneous fluorescence imaging. Cell viability is maintained during and after electrode wrapping around the cel and chemicals can diffuse into and out of the self‐folding devices. It is further shown that 3D spatiotemporal recordings are possible and that the action potentials recorded from cultured neonatal rat ventricular cardiomyocytes display significantly higher signal‐to‐noise ratios in comparison with signals recorded with planar extracellular electrodes. It is anticipated that this device can provide the foundation for the development of new‐generation MEAs where dynamic electrode–cell interfacing and recording substitutes the traditional method using static electrodes
Triazatruxene : a rigid central donor unit for a D-A3 thermally activated delayed fluorescence material exhibiting sub-microsecond reverse intersystem crossing and unity quantum yield via multiple singlet-triplet state pairs.

By inverting the common structural motif of thermally activated delayed fluorescence materials to a rigid donor core and multiple peripheral acceptors, reverse intersystem crossing (rISC) rates are demonstrated in an organic material that enables utilization of triplet excited states at faster rates than Ir‐based phosphorescent materials. A combination of the inverted structure and multiple donor–acceptor interactions yields up to 30 vibronically coupled singlet and triplet states within 0.2 eV that are involved in rISC. This gives a significant enhancement to the rISC rate, leading to delayed fluorescence decay times as low as 103.9 ns. This new material also has an emission quantum yield ≈1 and a very small singlet–triplet gap. This work shows that it is possible to achieve both high photoluminescence quantum yield and fast rISC in the same molecule. Green organic light‐emitting diode devices with external quantum efficiency >30% are demonstrated at 76 cd m−2
Intragranular Dispersion of Carbon Nanotubes Comprehensively Improves Aluminum Alloys

The room-temperature tensile strength, toughness, and high-temperature creep strength of 2000, 6000, and 7000 series aluminum alloys can be improved significantly by dispersing up to 1 wt% carbon nanotubes (CNTs) into the alloys without sacrificing tensile ductility, electrical conductivity, or thermal conductivity. CNTs act like forest dislocations, except mobile dislocations cannot annihilate with them. Dislocations cannot climb over 1D CNTs unlike 0D dispersoids/precipitates. Also, unlike 2D grain boundaries, even if some debonding happens along 1D CNT/alloy interface, it will be less damaging because fracture intrinsically favors 2D percolating flaws. Good intragranular dispersion of these 1D strengtheners is critical for comprehensive enhancement of composite properties, which entails change of wetting properties and encapsulation of CNTs inside Al grains via surface diffusion-driven cold welding. In situ transmission electron microscopy demonstrates liquid-like envelopment of CNTs into Al nanoparticles by cold welding.National Science Foundation (U.S.) (Grant DMR-1410636
Nanoscale coatings for ultralow dose BMP-2-driven regeneration of critical-sized bone defects

While new biomaterials for regenerative therapies are being reported in the literature, clinical translation is slow. Some existing regenerative approaches rely on high doses of growth factors, such as bone morphogenetic protein-2 (BMP-2) in bone regeneration, which can cause serious side effects. An ultralow-dose growth factor technology is described yielding high bioactivity based on a simple polymer, poly(ethyl acrylate) (PEA), and mechanisms to drive stem cell differentiation and bone regeneration in a critical-sized murine defect model with translation to a clinical veterinary setting are reported. This material-based technology triggers spontaneous fibronectin organization and stimulates growth factor signalling, enabling synergistic integrin and BMP-2 receptor activation in mesenchymal stem cells. To translate this technology, plasma-polymerized PEA is used on 2D and 3D substrates to enhance cell signalling in vitro, showing the complete healing of a critical-sized bone injury in mice in vivo. Efficacy is demonstrated in a Münsterländer dog with a nonhealing humerus fracture, establishing the clinical translation of advanced ultralow-dose growth factor treatment
Current status of outdoor lifetime testing of organic photovoltaics

I.D.W.S acknowledges support from the EPSRC (grant EP/L012294/1) and a Royal Society Wolfson Research Merit Award.Performance degradation is one of the key obstacles limiting the commercial application of organic photovoltaic (OPV) devices. The assessment of OPV stability and lifetime are usually based on simulated degradation experiments conducted under indoor conditions, whereas photovoltaic devices experience different environmental conditions under outdoor operation. Besides the intrinsic degradation of OPV devices due to the evolution of optoelectronic and morphological structure during long‐term operation, outdoor environmental changes can impose extra stresses and accelerate the degradation of OPV modules. Although outdoor studies on long‐term OPV stability are restricted by the long data collection times, they provide direct information on OPV stability under mixed degradation stresses and are therefore invaluable from the point of view of both research and practical application. Here, an overview of the current status of outdoor lifetime studies of OPVs is provided. After a summary of device lifetime extrapolated from indoor studies, outdoor lifetime testing platforms are introduced and the operational lifetime of various OPV devices are reviewed. The influence of climate and weather parameters on device performance and burn‐in phenomena observed during the degradation of OPVs is then discussed. Finally, an outlook and directions for future research in this field are suggested.Publisher PDFPeer reviewe
AIE multinuclear Ir(III) complexes for biocompatible organic nanoparticles with highly enhanced photodynamic performance.

The singlet oxygen (1O2) generation ability of a photosensitizer (PS) is pivotal for photodynamic therapy (PDT). Transition metal complexes are effective PSs, owing to their high 1O2 generation ability. However, non‐negligible cellular toxicity, poor biocompatibility, and easy aggregation in water limit their biomedical applications. In this work, a series of red‐emitting aggregation‐induced emission (AIE) Ir(III) complexes containing different numbers of Ir centers (mono‐, di‐, and trinuclear) and the corresponding nanoparticles (NPs) AIE‐NPs, are designed and synthesized. The increase of 1O2 generation ability is in line with the increasing number of Ir centers. Compared with the pure Ir(III) complexes, the corresponding NPs offer multiple advantages: (i) brighter emission; (ii) higher phosphorescence quantum yields; (iii) longer excited lifetime; (iv) higher 1O2 generation ability; (v) better biocompatibility; and (vi) superior cellular uptake. Both in vitro and in vivo experiments corroborate that AIE‐NPs with three iridium centers possess potent cytotoxicity toward cancer cells and effective inhibition of tumor growth. To the best of knowledge, this work is the first example of NPs of multinuclear AIE Ir(III) complexes as PSs for enhanced PDT. This study offers a new method to improve the efficiency of PSs for clinical cancer treatments
High-Performance Solution-Processed Amorphous-Oxide-Semiconductor TFTs with Organic Polymeric Gate Dielectrics

In this study we investigate the behavior of solution-processed metal-oxide-semiconductor transistors utilizing organic polymeric gate dielectrics. By adopting organic dielectrics covering a range of chemistries and relative permittivity values, we demonstrate the general outstanding performance of the resulting hybrid devices, which feature state-of-the-art charge-carrier mobility and the capability of low voltage operation, while allowing solution-based processing. Furthermore, we show the extraordinary stability of these transistors under constant-current bias stress.We gratefully acknowledge financial support from the European Commission through the POINTS project (FP7-NMP-2010-Small-4).This is the accepted manuscript. The final version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/aelm.201400024/abstract
Electroluminescence from Organometallic Lead Halide Perovskite - Conjugated Polymer Diodes

Organometallic lead perovskite-based solar cells can be converted to light-emitting diodes by engineering the current density. Diodes are fabricated with adjacent perovskite and conjugated polymer layers using orthogonal solvents. Under forward bias, these devices show simultaneous emission from both the luminescent conjugated polymer and the perovskite, providing direct information on electron and hole recombination as a function of device architecture and bias voltage.We gratefully acknowledge funding from the Engineering and Physical Sciences Research Council (EPSRC). A.K. acknowledges NRF-Singapore for a scholarship.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/aelm.20150000
Giant electric energy density in epitaxial lead-free thin films with coexistence of ferroelectrics and antiferroelectrics

Ferroelectrics/antiferroelectrics with high dielectric breakdown strength have the potential to store a great amount of electrical energy, attractive for many modern applications in electronic devices and systems. Here we demonstrate that a giant electric energy density (154 J×cm-3, 3 times the highest value of lead-based systems and 5 times the value of the best dielectric/ferroelectric polymer), together with the excellent fatigue-free property, good thermal stability and high efficiency, is realized in pulsed laser deposited (Bi1/2Na1/2)0.9118La0.02Ba0.0582(Ti0.97Zr0.03)O3 (BNLBTZ) epitaxial lead-free relaxor thin films with the coexistence of ferroelectric (FE) and antiferroelectric (AFE) phases. This is endowed by high epitaxial quality, great relaxor dispersion and the coexistence of the FE/AFE phases near the morphotropic phase boundary (MPB). The giant energy storage effect of the BNLBTZ lead-free relaxor thin films may make a great impact on the modern energy storage technology
Ligand-induced control of photoconductive gain and doping in a hybrid graphene-quantum dot transistor

Recent advances in graphene-based electronics range from the\ud
discovery of fundamental physical phenomena to the development\ud
of new high-performance photosensitive devices. [ 1–5 ]\ud
These applications exploit not only the unique electronic properties\ud
of graphene but also additional functionalities that can be\ud
achieved by capping the graphene layer with another material\ud
or nanostructure, e.g., atomically thin fi lms, [ 6,7 ] carbon nanotubes\ud
[ 8 ] or inorganic nanoparticles. [ 8–10 ] Colloidal semiconductor\ud
quantum dots (QDs) are of particular interest as their optical\ud
properties can be fi ne-tuned by varying their size and/or composition.\ud
[ 11 ] In addition, colloidal synthesis enables QDs to be\ud
functionalized by doping [ 12 ] and/or surface encapsulation. [ 13 ]\ud
Recently, a photoresponsivity of 10 7\ud
 A W −1\ud
 was achieved by\ud
depositing QDs on graphene and explained in terms of trapping\ud
of photoexcited carriers on the QDs and charge transfer between\ud
them and the graphene layer. [ 9,10 ] This mechanism should be\ud
strongly dependent on the interface between the QDs and graphene.\ud
Furthermore, the ligands that encapsulate the QDs may\ud
provide a means of modifying the transfer of electronic charges\ud
and enhancing the electronic properties of the graphene layer.\ud
 Here, we investigate the properties of single layer graphene\ud
(SLG) functionalized with an overlayer of near-infrared PbS\ud
colloidal quantum dots capped with thioglycerol/dithioglycerol\ud
or polyethylene glycol (PEG500 and PEG2000). We demonstrate\ud
that the polarity of the conductivity and the carrier\ud
concentration can be modifi ed, and photoresponsivity of SLG\ud
can be signifi cantly enhanced by the choice of ligands. By\ud
reducing the length of capping ligands, hence the thickness\ud
of the dielectric barrier between the QDs and the SLG, and by\ud
preserving the integrity of the ligand layer, we achieve the effi -\ud
cient transfer of photogenerated carriers from the QDs to the\ud
graphene before recombining, resulting in enhanced photoresponsivities\ud
of up to ≈10 9\ud
 A W −1
Local distortions in nanostructured ferroelectric ceramics through strain tuning

Ferroelectric materials are highly sensitive to grain size reduction because strain and ferroelectric polarization have a direct connection. Using 15 nm (Ba,Sr)TiO 3 particles obtained by advanced supercritical synthesis and their densifi cation by high-pressure spark plasma sintering under air, reproducible and dense nanostructured ceramics are achieved. Taking advantage of the high pressure (up to 600 MPa) applied during the sintering step, the internal stress generated at the grain scale can be monitored to compensate for the particle surface stress due to size effect. Both the local dynamics observed by Raman scattering and the overall dielectric behavior consistently indicate a recovery of the ferroelectric properties as the sintering pressure is increased. This unique behavior shows that low-temperature and high-pressure processing enables designing nanostructured functional ceramics exhibiting original properties
Controlling the Electrical Properties of Undoped and Ta-doped TiO2 Polycrystalline Films via Ultra-Fast Annealing Treatments

We present a study on the crystallization process of undoped and Ta doped TiO2 amorphous thin films. In particular, the effect of ultra-fast annealing treatments in environments characterized by different oxygen concentrations is investigated via insitu resistance measurements. The accurate examination of the key parameters involved in this process allows us to reduce the time needed to obtain highly\ud
conducting and transparent polycrystalline thin films (resistivity ~ 6 × 10^(-4) Ωcm, mean transmittance in the visible range ~ 81%) to just 5 minutes (with respect to the 180 minutes required for a "standard" vacuum annealing treatment) in nitrogen atmosphere (20 ppm oxygen concentration) at ambient pressure. Experimental evidence of superficial oxygen incorporation in the thin films and its detrimental role for the conductivity are obtained by employing different concentrations of traceable 18O isotopes during ultra-fast annealing treatments. The results are discussed in view of the possible implementation of the ultra-fast annealing process for TiO₂-based transparent conducting oxides as well as electron selective layers in solar cell devices; taking advantage of the high control of the ultra-fast crystallization processes which has been achieved, these two functional layers are shown to be obtainable from the crystallization of a single homogeneous thin film
Ohmic contacts to 2D semiconductors through van der Waals bonding

High contact resistances have blocked the progress of devices based on MX2 (M
= Mo,W; X = S,Se,Te) 2D semiconductors. Interface states formed at MX2/metal
contacts pin the Fermi level, leading to sizable Schottky barriers for p-type
contacts in particular. We show that (i) one can remove the interface states by
covering the metal by a 2D layer, which is van der Waals-bonded to the MX2
layer, and (ii) one can choose the buffer layer such, that it yields a p-type
contact with a zero Schottky barrier height. We identify possible buffer layers
such as graphene, a monolayer of h-BN, or an oxide layer with a high electron
affinity, such as MoO3. The most elegant solution is a metallic M'X'2 layer
with a high work function. A NbS2 monolayer adsorbed on a metal yields a high
work function contact, irrespective of the metal, which gives a barrierless
contact to all MX2 layers
Low-Temperature Solution-Processed Electron Transport Layers for Inverted Polymer Solar Cells

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimProcessing temperature is highlighted as a convenient means of controlling the optical and charge transport properties of solution processed electron transport layers (ETLs) in inverted polymer solar cells. Using the well-studied active layer – poly(3-hexylthiophene-2,5-diyl):indene-C60 bisadduct – the influence of ETL processing temperatures from 25 to 450 °C is shown, reporting the role of crystallinity, structure, charge transport, and Fermi level (EF) on numerous device performance characteristics. It has been determined that an exceptionally low temperature processed ETL (110 °C) increases device power conversion efficiency by a factor greater than 50% compared with a high temperature (450 °C) processed ETL. Modulations in device series and shunt resistance, induced by changes in the ETL transport properties, are observed in parallel to significant changes in device open circuit voltage attributed to changes on the EF of the ETLs. This work highlights the importance of interlayer control in multilayer photovoltaic devices and presents a convenient material compatible with future flexible and roll-to-roll processes