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Sr-doped LaMnO 3 (LSM) is a conventional cathode material for traditional solid oxide fuel cells (SOFCs), but its application in proton-conducting SOFCs is unsatisfactory due to the lack of catalytic activity of LSM at intermediate temperatures. Various strategies have been employed to optimize LSM performance, but no radiative element has been utilized. In this study, uranium was used to modify LSM. The U-doped LSM (LSMU) was not a pure phase but rather a mixture of LSM and SrUO 4. The formation of oxygen vacancy was promoted at the LSM/SrUO 4 interface, as indicated by first-principles calculations and experimental studies, potentially enhancing the oxygen reduction reaction (ORR) activity of the material. Using LSMU as the cathode, the proton-conducting SOFC (H–SOFC) reaches a peak power density of 1206 mW cm−2 at 700 °C, significantly greater than the LSM cell, which reached only 522 mW cm−2 under the same testing conditions. In addition, the current LSMU cell demonstrated the highest power output for LSM-based H–SOFCs to date, proving the LSUM to be an effective cathode for H–SOFCs. This study demonstrated a potential method for immobilizing uranium in a perovskite cathode oxide with improved performance for H–SOFCs. [ABSTRACT FROM AUTHOR]

The formation of Cu 2 O films from an alkaline copper-lactate electrolyte using potentiostatic pulse electrodeposition has been conducted. The effects of the frequency, duty cycle, potential amplitude and electrolyte composition during pulsed electrodeposition on the resulting Cu 2 O morphology, crystal structure and orientation have been investigated in detail. Comparisons are made with films produced by potentiostatic DC deposition in the same electrolyte. An increase in the pulse frequency or reduction in the duty cycle causes the Cu 2 O grains to become less cubic and more spherical as the crystal growth in the 〈111〉 direction becomes less dominant and growth in the 〈100〉 direction becomes more favored. Higher Cu(II) concentration, lower electrolyte pH and smaller cathodic overpotential have a similar effect and leads to the formation of Cu 2 O crystals with distinct or truncated octahedral shapes through pulsed electrodeposition. Overall, the application of a pulsed potential waveform during Cu 2 O electrodeposition in alkaline electrolyte enables the formation of Cu 2 O films with controllable morphology with lesser need to alter the electrolyte composition or temperature. [ABSTRACT FROM AUTHOR]

Mesoporous carbon materials have been widely used as hosts for sulfur encapsulation to mitigate the low electrical conductivity of sulfur, lithium polysulfide shuttle, and drastic volume changes of sulfur species associated with lithium-sulfur batteries (LSBs). The ideal sulfur-host composite should have an optimal content of sulfur that partially fills the pores of the host and produces the exact amount of final discharged product Li 2 S that can be completely accommodated by the pores of the host. However, accurately determining this optimal content of sulfur is a challenge and no effective method has been established. In this work, we successfully determined the optimal sulfur content for the Ketjenblack EC-600 JD (KB) sulfur host by simply characterizing sulfur-KB (SKB) composites with different sulfur contents using X-ray diffraction (XRD) spectroscopy coupled with thermogravimetric analysis (TGA). The LSB using the SKB with the optimal sulfur content of 52.9% showed a high specific capacity of 1535 mAh g−1 at 0.1C and a capacity of 680 mAh g−1 even at the high rate of 5C. Furthermore, it also showed stable cycling stability with low capacity decay rates of 0.05% and 0.09% per cycle over 500 cycles at 2C and 5C, respectively. [Display omitted] • A method to accurately determine the optimal sulfur content is developed. • The influence of void space in Ketjenblack pores is investigated. • A high specific capacity and stable cycling stability is achieved for lithium sulfur battery. [ABSTRACT FROM AUTHOR]

Abstract We report the electrodeposition of cuprous oxide (Cu 2 O) films from cupric sulfate-lactate electrolytes at high pH 13.5 and their performance in all-oxide fluorine-doped tin oxide/Cu 2 O/aluminium-doped zinc oxide solar cells. The deposit grains are found to grow with rather randomly distributed <111> and <100> crystal orientations and have a poorly-definded morphology with evidence of chemical dissolution that takes place during the deposition process. Significant improvements in the solar cell performance with high power conversion efficiencies of up to 1.55% is achieved, which is much better that those (<0.2%) of solar cells with Cu 2 O layer electrodeposited at lower pH. The performance enhancement is primarily attributed to the improved electron transport in the Cu 2 O thin film due to partial merging of grains. Highlights • Cu 2 O electrodeposited at pH 13.5 has poorly-defined grains with mixed orientations. • Chemical dissolution becomes significant at high electrodeposition pH. • Solar cell performance is improved with partially merged grains. • Optimal power conversion efficiency of ~1.55% is obtained. • Cu 2 O with poorly-defined grains has high electron mobility. [ABSTRACT FROM AUTHOR]

Temperature sensors convert non-electrical physical quantities into electrical quantities using the temperature-dependent properties of their core part, such as resistance/capacitance, for accurate temperature measurement and device control. Thanks to the universality of temperature sensor, it is widely applied in industrial production, medical electronics, food processing, national defense and military. Compared with the traditional temperature sensor, which has the shortcoming of large volume and high cost, the Micro Electro Mechanical Systems (MEMS) temperature sensor has more advantages in miniaturization and integration. As a representative of two-dimensional (2D) material, graphene has the characteristics of large specific surface area, high thermal conductivity and high carrier mobility. It stands out among carbon-based sensitive materials as the obvious choice for temperature sensors' fabrication. In this paper, the development history of graphene-based MEMS temperature sensors is introduced. The main mechanism of graphene's sensitivity to temperature is discussed. Then, the recent research status of graphene-based temperature sensors is listed. By comparing the performance of graphene temperature sensors with different materials and structures, the current application of them in different fields is analyzed. Finally, the future development direction of graphene temperature sensors is mentioned, which provides a new idea for the design and fabrication of graphene-based temperature sensors with higher performance. • Introduced the development history of graphene-based temperature sensors in details. • Explained systematically the temperature-sensitive mechanisms of graphene to provide a theoretical foundation for the sensors. • Compared the electrical and thermal properties of graphene-based temperature sensors with different materials and structures. In addition, analyzed their current application fields. • Predicted the future development direction of graphene-based temperature sensors. [ABSTRACT FROM AUTHOR]

Abstract: Several diketopyrrolopyrrole derivative based dyes (DPP), combined with an iodonium salt or an amine (and optionally an additive), are studied as photoinitiating systems for the cationic polymerization CP of epoxides or the free radical polymerization FRP of acrylates under different irradiation sources i.e. a very soft halogen lamp as well as laser diodes at 473 nm (blue light) and 532 nm (green light). The diketopyrrolopyrrole-furan derivative (FuDPP) is very efficient in CP. The structure/reactivity/efficiency relationships in this series of DPP derivatives are investigated. A comparison with a well known reference for visible light photoinitiating system (i.e. camphorquinone based photoinitiating system) is also provided showing the better efficiency of the new proposed structures. The photochemical mechanisms are studied by steady state photolysis, fluorescence, cyclic voltammetry, laser flash photolysis and electron spin resonance spin-trapping techniques. [Copyright &y& Elsevier]

A facile and moderate to high yielding protocol is reported for the synthesis of 2,7-bis(5-bromothiophen-2-yl)-3,8-bis(2-decyltetradecyl)-3,8-dihydropyrimido[4,5- g ]quinazoline-4,9-dione, which can be potentially used to synthesize other pyrimido[4,5- g ]quinazoline-4,9-diones. Moreover, new pyrimido[4,5- g ]quinazoline-4,9-diones synthesized by this route can potentially be used as organic semiconductors. [ABSTRACT FROM AUTHOR]

We report the synthesis of an aromatic amine-containing polymer ( PDPAT-12 ) and the use of this polymer as an effective additive to an ambipolar polymer semiconductor ( PIBDFBT-e37 ) to realize unipolar n-type charge transport in organic thin film transistors (OTFTs). With 10 wt% PDPAT-12 addition to PIBDFBT-e37 , the OTFTs achieved unipolar n-type charge transport with electron mobility of up to 0.42 cm 2 V −1 s −1 in nitrogen and 0.19 cm 2 V −1 s −1 in air. Moreover, the polymer blend demonstrated improved stability towards ambient air (retaining 50% of its initial electron mobility after exposed in air for 28 days) than the pristine PIBDFBT-e37 (retaining 13% of its initial electron mobility under the same conditions) and the PIBDFBT-e37 :PEI (polyethylenimine) blend, which lost transistor behaviour almost instantly once exposed to ambient air. Our results show that the use of this aromatic amine-containing polymer as an additive can convert an ambipolar polymer into an n-type unipolar polymer in OTFTs with much improved air stability. [ABSTRACT FROM AUTHOR]

A series of electron-acceptor polymers, copolymers and blends were used in all-polymer BHJ photodetectors and the effect of acceptor compositions on the key device parameters of dark current density and photocurrent was investigated. Compared with acceptor polymers and polymer blends, the devices based on acceptor copolymer showed lowered dark current and higher photocurrent, due to optimal molecular stacking and morphology of the BHJ active layer. The acceptor blends tend to cause a large phase separation and rough surface of the active layer, thus leading to a low detectivity of the device. Among all the acceptor compositions studied in this work, the all-polymer BHJ photodetector based on a donor polymer ( PolyD ) and an acceptor copolymer ( PolyAA′50 ) exhibited the highest specific detectivity of over 10 12 Jones in the spectral region of 320–980 nm under −0.1 V bias. [ABSTRACT FROM AUTHOR]

[Display omitted] • Boosted catalytic activity of Hollow Ag/Mn(btc) composite with respect to individual systems. • Sulphides are selectively oxidised to sulfoxides in good to outstanding yields. • Low-cost, easy availability, and excellent chemoselectivity make this methodology a valid contribution to the existing processes in the field of oxidation of organic sulphides. • Composite catalyst maintained good photocatalytic recyclability. By templating silver and Mn(btc) growth on polystyrene beads, hollow Ag-Mn(btc) nanospheres with uniform shell thickness are created. The Ag-Mn(btc) sample was characterized by various techniques including Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), N 2 Adsorption-desorption (BET-BJH), thermal analysis (TGA-DTG) and X-ray photoelectron spectroscopy (XPS). The morphology of the Ag/Mn(btc) was also studied using scanning electron microscope (SEM) and tunneling electron microscope (TEM). Using 30 percent H 2 O 2 and catalytic quantities of an unique recoverable hollow Ag/Mn(btc) catalyst, several aromatic and aliphatic sulphides are selectively oxidised to sulfoxides in good to outstanding yields (79%-95%). Under the given reaction conditions, the catalyst may be recovered and reused for at least six reaction cycles without significant reactivity loss. [ABSTRACT FROM AUTHOR]

In this study, we added several aromatic amine compounds as dopants to an ambipolar polymer semiconductor, PDBTAZ, and studied the charge transport behavior of the doped polymer thin films in organic thin film transistors. The trap energy ( E T ), which is the HOMO energy difference between the amine dopant and the polymer, was found related to the hole transport suppression effect of these amines. For an amine with E T < 0.25 eV, at a 2% dopant concentration, little changes in the hole transport characteristics of the doped polymer films were observed. In contrast, for an amine with E T > 0.25 eV, complete hole transport suppression was realized. This study offers a useful approach to converting an ambipolar polymer semiconductor into a unipolar n-type polymer semiconductor. [ABSTRACT FROM AUTHOR]

The morphology of nanocrystalline MoSe 2 is fine-tuned by optimizing the MoSe 2 content encapsulated in the N-doped porous carbon nanofibers to maximize the heterointerfaces of dichalcogenide/carbon matrix that function as active sites for high performance potassium-ion storage. [Display omitted] • Ultra-small few-layered MoSe 2 nanosheets are encapsulated in N-PCNFs. • The morphology of nanocrystalline MoSe 2 is fine-tuned to maximize the heterointerfaces. • The heterointerfaces function as active sites for highly efficient potassium-ion storage. • The confinement of porous carbon matrix accommodates the volume change during cycling. MoSe 2 has recently attracted great interest in the development of high-performance potassium-ion batteries (PIBs) anode materials because of its high theoretical capacity. However, the practical application of MoSe 2 in PIBs is still hampered by its low conductivity and large volumetric expansion upon cycling. In this work, ultra-small few-layered MoSe 2 nanosheets are encapsulated in N-doped porous carbon nanofibers (N-PCNFs) by an electrospinning and in situ carbonization/selenization process to form MoSe 2 /N-PCNFs nanocomposites. The morphology of nanocrystalline MoSe 2 is fine-tuned to maximize the heterointerfaces of dichalcogenide/carbon matrix that function as active sites for potassium-ion storage. Benefitting from the effective confinement of MoSe 2 in the carbon matrix and the robust chemical bonds (C Se and C Mo) formed at the heterointerfaces, the structure stability and charge transfer kinetics of MoSe 2 /N-PCNFs are significantly improved. Moreover, the one-dimensional structure of N-PCNFs accelerates ions/electrons-transfer kinetics. The optimized MoSe 2 /N-PCNF with a moderate MoSe 2 content exhibits excellent electrochemical performance for PIBs. The electrochemical storage mechanism of MoSe 2 /N-PCNFs is investigated by in situ X-ray diffraction measurements. Density functional theory calculations verify the enhanced adsorption of potassium-ion and electron transport at the heterointerfaces. This work provides new insights into the design of MoSe 2 based anodes for high-performance PIBs and other advanced secondary batteries. [ABSTRACT FROM AUTHOR]

We report the synthesis of a novel electron acceptor building block, fluorene-fused triphenodioxazine ( FTPDO ), and a donor-acceptor polymer based on FTPDO and bithiophene, PFTPDOBT . This new polymer possesses a narrow band gap (1.66 eV) with low-lying frontier energy levels and exhibits hole transport characteristics in organic thin film transistors (OTFTs). Thin films of PFTPDOBT show remarkable thermal stability in air at temperatures of up to 250 °C with no noticeable differences in UV–Vis absorption characteristics in comparison to the films annealed in nitrogen. Surprisingly, OTFTs with the polymer thin films annealed in air and measured in air outperform significantly the devices annealed and measured in nitrogen. [ABSTRACT FROM AUTHOR]

A novel acceptor building block, 3,7-bis(( E )-2-oxoindolin-3-ylidene)-3,7-dihydrobenzo[1,2- b :4,5- b′ ]dithiophene-2,6-dione (IBDT), is developed to construct a donor-acceptor polymer PIBDTBT-40 . This polymer has favorable highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels for balanced ambipolar charge transport. Organic thin film transistors (OTFTs) based on this polymer shows well-balanced ambipolar characteristics with electron mobility of 0.14 cm 2 V −1 s −1 and hole mobility of 0.10 cm 2 V −1 s −1 in bottom-gate bottom-contact devices. This polymer is a promising semiconductor for solution processable organic electronics such as CMOS-like logic circuits. [ABSTRACT FROM AUTHOR]

A trimer of diketopyrrolopyrole (DPP), Tri-BTDPP, was synthesized and characterized. Tri-BTDPP has a HOMO level of −5.34 eV, a low band gap of 1.33 eV, and a hole mobility of ∼10 −3 cm 2 V −1 s −1 in organic field effect transistors (OFETs). Organic photovoltaic (OPV) devices using the donor/acceptor blends of Tri-BTDPP and PC 71 BM exhibited low power conversion efficiencies (PCE) of up to 0.72%, even though the desirable optical and electronic characteristics of this compound as a donor semiconductor for achieving high performance for OPV. Through an intensive study of the active layer using AFM, XRD, and DSC, it was found that Tri-BTDPP and PC 71 BM were unable to intermix and formed oversized Tri-BTDPP phases, resulting in poor charge separation. Some guidance on how to improve the OPV performance of Tri-DPP compounds is provided. [ABSTRACT FROM AUTHOR]

A novel "micro-tailoring" strategy is proposed for microstructure customizing of g-C 3 N 4 to confine atomically dispersed Ru cocatalysts toward efficient photocatalytic H 2 evolution. [Display omitted] • A micro-tailoring strategy is proposed for micro-structure customization of g-C 3 N 4. • Defects, boundaries, dopants and exposed groups are created in the tailored g-C 3 N 4. • Ru single atoms are stably anchored on the surface of the tailored g-C 3 N 4. • Strong metal − support interaction of Ru on tailored g-C 3 N 4 enhances the photocatalytic activity. Loading single atom (SA) cocatalysts onto semiconductors offers great potential for improving the photocatalytic performance. Here, we report a simple micro-tailoring strategy that cuts g-C 3 N 4 into small pieces and oligomers. Defects, boundaries, dopants and terminal groups created could confine Ru SAs stably onto the framework, ensuring uniform dispersion of Ru SAs on the tailored g-C 3 N 4. The as-prepared composite, the tailored g-C 3 N 4 loaded with Ru SAs, showed a dramatic increase photocatalytic activity for H 2 evolution (4052.1 μmol h−1 g−1) compared to the composite of the non-tailored g-C 3 N 4 loaded with Ru (394.3 μmol h−1 g−1). The enhanced catalytic activity was achieved by the metal-support interaction between the Ru atoms and the tailored g-C 3 N 4 , which could manipulate local charge distribution, thus promoting the adsorption of intermediates and enabling efficient charge transfer. In addition, atomic Ru-sites could provide directional charge transfer channels and targeting sites to facilitate rapid photo-introduced charge transfer and water reduction reaction. The proposed strategy provides a facile and feasible way for the construction of atomically dispersed catalysts for efficient photocatalytic H 2 evolution and other reactions. [ABSTRACT FROM AUTHOR]

Two new π-conjugated polymers with donor backbone and π-conjugated indolin-2-one side chains, PBDTTI and PBDTTIF, are designed and synthesized as wide bandgap donors for non-fullerene acceptor-based organic solar cells (OSCs). The monomers containing electron accepting indolin-2-one side chains, (Z)-3-((2,5-dibromothiophen-3-yl) methylene)-1-methylindolin-2-one (M1) and (Z)-3-((2,5-dibromothiophen-3-yl) methylene)-5-fluoro-1-methylindolin-2-one (M2), can be easily synthesized via Knoevenagel condensation between 2,5-dibromothiophene-3-carbaldehyde and 2-oxindole or 5-fluoro-2-oxindole, respectively. Stille coupling polymerization of the electron donating benzodithiophene (BDT)-containing monomer 1,1′-[4,8-bis [5-(2-ethylhexyl)-2-thienyl]benzo [1,2- b :4,5- b ′]dithiophene-2,6-diyl]bis [1,1,1-trimethylstannane] and M1 or M2 produced PBDTTI or PBDTTIF, respectively. The strong electron accepting π-conjugated 1-methylindolin-2-one and 5-fluoro-1-methylindolin-2-one side chains can achieve low-lying HOMO energy levels of −5.59 eV for PBDTTI and −5.60 eV for PBDTTIF, which is beneficial for realizing high open circuit voltage (V OC) of the resulting OSCs. On the other hand, since the electron acceptor units are on the side chains, the polymer backbone containing only electron donor units could maintain wide bandgaps of 1.91 eV and 1.89 eV for PBDTTI and PBDTTIF, respectively. When PBDTTI and PBDTTIF were used as donors and a small bandgap non-full acceptor ITIC as an acceptor, the resulting OSCs devices achieved V OC of 0.97 and 1.00 V, short circuit current densities (J SC) of 15.60 and 13.70 mAcm-2, and fill factors (FF) of 0.60 and 0.59, resulting in power conversion efficiencies of 8.00 and 7.70%, respectively. [Display omitted] • Two new donor-backbone and acceptor-side chain polymer donors are synthesized. • Low frontier energy levels and wide bandgap are achieved. • Organic solar cells using these polymer donors showed promising performance. [ABSTRACT FROM AUTHOR]

Abstract: Rather consistent power conversion efficiencies have been achieved in organic solar cells throughout a wide range of active layer thicknesses (∼100nm to ∼800nm) by using a p-type polymer semiconductor with high hole transport mobility (∼1cm2 V−1 s−1) as the donor, and PC61BM as the acceptor. A comparison between standard and inverted device configurations demonstrates that the inverted configuration is more suitable for achieving thicker active layers when a high hole mobility donor is used. We attribute this to the longer hole collection path in the inverted structure, which can benefit from using a high hole mobility material. Our results will be very useful for the development of new semiconductor materials and the design of device structures for more feasible manufacturing of large area OPV devices via high speed roll-to-roll printing processes. [Copyright &y& Elsevier]

Abstract: Alkyl amine stabilized gold nanoparticles (Au-NPs), with diameters of 1–10nm, deposited at the interface of the hole-collecting buffer layer [poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)] and poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT):(PCBM) active layer were found to significantly reduce solar cell performance. The reduced performance was attributed to interactions between the amine based organic stabilizers and the PEDOT:PSS buffer layer. This was confirmed by screening various organic stabilizing ligands at the interfacial layer and measuring the resulting solar cell performances. In addition, it was found that alkyl thiol capped Au-NPs (5–10nm) incorporated at the buffer layer and their corresponding alkyl thiol stabilized ligands had a lesser impact on the overall performance of the polymer solar cells. [Copyright &y& Elsevier]

Abstract: The effect of molybdenum trioxide (MoO3) as an interlayer is investigated on device performance of organic solar cells using zinc phthalocyanine (ZnPc):fullerene-C60 (C60) as the active layer. Our results indicate that the insertion of MoO3 has little effects on the surface topography or absorption properties, but noticeably increases the shunt resistance, which leads to the improvement of open-circuit voltage, short-circuit current and fill factor. As a result, the power conversion efficiency (PCE) of the devices can be improved by up to 25%. An optimum PCE of 3.43% was achieved with the insertion of 10nm MoO3. [Copyright &y& Elsevier]

Abstract: Influences of the temperature (Ts) for spray pyrolysis deposition of TiO2 blocking layer (BL) using titanium diisopropoxide bis(acetylacetonate) (TAA) as a precursor and the temperature (Tp) for post-annealing of the BL films on the resulting BL film morphology and photovoltaic performance of solid-state dye-sensitized solar cells (SDSC) are investigated. A Ts ranging from 300 to 400°C is found preferable for the formation of BL films with smooth surface and dense grain packing. A Ts lower than 300°C results in insufficient decomposition of the TAA precursor and is unable to form smooth BL films, while a Ts over 400°C leads to loosely packed grain in BL films. Power conversion efficiency (PCE) of ~4.0% is obtained for SDSC devices with BL films prepared at a Ts in the range of 300–450°C. High temperature post-annealing (Tp =500–550°C) of the BL films prepared at a low Ts, such as 300°C, can improve the PCE up to 4.6%. The improvements are considered due to the higher purity, increased crystallinity, and retained high grain packing density of the post-annealed BL films, which facilitate charge transport and suppress charge recombination. [Copyright &y& Elsevier]