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While lithium-sulfur batteries (LSBs) have tremendous potential in capacity and energy, their application in practice is limited by short cycle life, slow reaction kinetics, and underutilization of sulfur. To tackle these challenges, we have developed a multifunctional host consisting of sandwich-type CoSe 2 -CNWs@NG that were hydrothermally synthesized through self-assembly of CoSe 2 -embedded carbon nanowires (CoSe 2 -CNWs) with N-doped graphene (NG). Through the implementation of CoSe 2- CNWs@NG as a host material, active sulfur can be effectively intercalated within the interlayer spaces of neighboring NG layers. The extensive contact area between sulfur and NG sheets facilitates rapid electron transfer, thereby maximizing sulfur utilization. N-doped graphene and polar CoSe 2 provide sufficient chemisorption sites for polysulfides, while the catalytic activity of CoSe 2 promotes polysulfide conversion. In addition to building a good conductivity structure for fast carrier transport and electrolyte diffusion, the sandwich structure of CoSe 2 -CNWs@NG physically restricts polysulfides and buffers substantial sulfur volume changes during cycling. As a result, the CoSe 2 -CNWs@NG/S cathode possessing high-load sulfur capacity (4.06 mg cm−2) exhibits superior cell performance at an ultrahigh rate as well as low E/S ratio. After 1000 cycles at 10 C, it achieves a remarkable reversible capacity of 314.4 mAh g−1 with an impressively low average fading rate of 0.023 % per cycle. Even at a low E/S ratio of 5 μL mg−1, the cathode exhibits remarkable performance, retaining a reversible capacity of 628.2 mAh g−1 after 150 cycles at the rate of 1 C. [ABSTRACT FROM AUTHOR]

New breakthroughs are expecting to be achieved based on the discovery of novel interfacial materials for polymer solar cells (PSCs). Herein, the simple and facial approach of spin-coating technology with post heat and ultraviolet-ozone treatment is performed on niobium oxalate to prepare Nb 2 O 5 interfacial layer with ultra-high transmittance. The ultraviolet photoemission spectroscopy results confirm that Nb 2 O 5 with a work function of 4.85 eV is suitable for employing as anode buffer layer (ABL). The average power conversion efficiencies (PCEs) of the P3HT:PCBM-based fullerene devices with Nb 2 O 5 ABL reaches to 4.01%, surpassing that (3.69%) of the control devices with ITO/PEDOT:PSS ABL. Further investigations on the PBDB-T:ITIC-based non-fullerene PSCs with Nb 2 O 5 ABL demonstrate that a PCE as high as 8.67% can be reached, which is superior to that of device modified by PEDOT:PSS ABL (8.03%). Namely, 8% efficiency improvement in PSCs based on fullerene and non-fullerene acceptors realized as compared to the control devices with PEDOT:PSS ABL. [ABSTRACT FROM AUTHOR]

For organic-inorganic hybrid perovskite solar cells (PerSCs), the crystallinity and the grain size of the perovskite films are crucial for effective exciton dissociation and charge transportation. Herein, we introduce methylammonium halide (MABr and MACl) intermediates to control the perovskite formation processes via intramolecular exchange. X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS) are used to monitor the transition from intermediate to perovskite. It is particularly noteworthy that as Cl - and MA + are removed from the film as MACl vapor, the intermediate derived from Cl-Hybrid eventually turns into FAPbI 3 perovskite after thermal annealing. The morphology, crystallinity, fluorescence lifetime and the stability of perovskite films derived from different methylammonium halide intermediates are also investigated, and PerSCs based on different perovskite films are fabricated. The PerSCs derived from MACl intermediate exhibit the best photovoltaic performance with a PCE of 19.16%, and the PCE reaches 15.87% for MABr intermediated PerSCs, much higher than that (13.72%) of the control device without methylammonium halide intermediates. Furthermore, MACl intermediated PerSCs demonstrate the best stability due to the highest crystallinity. Our findings indicate that methylammonium halide intermediating is a feasible and effective approach to acquire high crystallinity of perovskite film for high performance and stable PerSCs. [ABSTRACT FROM AUTHOR]

The photon harvesting of the photoactive layer within a multilayered polymer solar cells (PSCs) greatly affects the output electric power of the devices. For PSCs, the device performance is very sensitive to the photoactive layer thickness. Therefore, how to enhance the light absorption of the photoactive film with fixed thickness is still a big challenge. Plasmonic enhancement induced by noble metal nanoparticles has been proved to be an effective way to enhance light trapping inside the photoactive film without increasing the thickness of film. By incorporating Au decahedra into the poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) anode buffer layer, high performance plasmonic PSCs based on P3HT:PC 60 BM and PBDT-TS1:PC 70 BM were fabricated and the light response of the PSCs are greatly improved in a broadband wavelength, resulting in a remarkable enhancement in short-circuit current density. The calculation results of finite difference time domain (FDTD) confirm that the plasmonic effects induce enhancement in device performance. Upon optimization, the best power conversion efficiency (PCE) of the device based on P3HT:PC 60 BM and PBDT-TS1:PC 70 BM reaches 4.14% and 10.29%, respectively, among the best values reported in literature. These results can provide valuable guidelines for the design of metal nanostructures for organic photovoltaic applications. [ABSTRACT FROM AUTHOR]

For polymer solar cells (PSCs), the interfaces between the back and front contacts with the photoactive layer play a crucial role for charge extraction. Herein, we demonstrate high performance PSCs with dual functional tantalum methoxide (Ta-OMe) cathode interfacial layer, which can reduce the interface energy barrier and form a light trapping structure with reflective metal electrode. The energy level of Ta-OMe is investigated by ultraviolet photoelectron spectroscopy (UPS). The composition of the Ta-OMe film is confirmed by X-ray photoelectron spectroscopy (XPS). The surface morphologies of the photoactive layer with and without Ta-OMe layer are measured by scanning electron microscopy (SEM) and tapping mode atomic force microscopy (AFM). Three polymer donors with different band gaps and two classical fullerene acceptors were selected as photoactive materials for fabrication PSCs. The PSCs with Ta-OMe interfacial layer exhibit superior performance in comparison with devices which Al and Ca/Al based devices. The great enhancement in J sc is associated with additional absorption (Δα Abs ) and the additional EQE (Δα EQE ). The four parameters of V oc , J sc , FF, and PCE for device with Ta-OMe reach 0.80 V, 18.55 mA/cm 2 , 70%, and 10.18%, respectively, among the best values reported for PTB7-Th:PC 70 BM based PSCs. [ABSTRACT FROM AUTHOR]

Unbalanced photocurrent output for each sub-cell in monolithic multiple junction solar cells (MMJ-SCs) reduces the achievable photovoltaic power efficiency (PCE). Here, we first introduce Au decahedra nanoparticles to realize the plasmon-enhanced photo-absorption of GaInP top-cell and achieve the current-matched MMJ-SCs. By simply spin-coating the Au decahedral nanoparticles on the illuminated surface of the devices, the PCEs of the monolithic double junction and triple junction solar cells increase significantly from 27.01% to 28.63% and from 29.88% to 31.90%, respectively. Both the theoretical local electromagnetic distributions and the experimental extinction properties confirm the plasmonic induced absorption enhancement in device performance, and further elucidate the essential reason for photocurrent enhancement derives from the more furious oscillation of free electrons in the vicinity of sharp vertexes for Au decahedra nanoparticles. Our results demonstrate that Au decahedra with sharp vertexes and edges are promising for meliorating the trade-off between light absorption and carrier collection in GaInP top-cell. In addition, this facile and simple strategy also highlights non-annealing treatment and prevents the impurity diffusion at high temperature for MMJ-SCs, and may facilitate other types of solar-harvesting devices. [ABSTRACT FROM AUTHOR]

• Theoretical analysis indicates lower binding energy (E b) can reduce the V oc loss. • A theoretical PCE of 18.86% was obtained via optimizing the E b values. • PM6:Y6 film with a 0.14 eV E b was achieved via optimizing the CN concentration. • PM6:Y6-based devices with a 0.14 eV E b reach a PCE of 16.14%. • Short electron-hole pair binding distances (a) can further reduce V oc losses. The energy loss during exciton dissociation is one of key reasons for organic solar cells (OSCs) with inferior performance. Herein, a theoretical and experimental guidance for highly efficient OSCs with outstanding exciton dissociation rate is introduced via fine-tuning the binding energy (E b) and the electron-hole pair binding distance (a) in the charge transfer (CT) state. Results suggest that decreasing the E b appropriately is favorable for higher photovoltaic conversion efficiency (PCE). Hence, we attempt to modulate the E b of PM6:Y6 photoactive layer by changing additive and their corresponding concentration. Investigations show that the E b of PM6:Y6 changes slightly with different additives, and the chloronaphthalene (CN) with appropriate concentration affords an E b of 0.14 eV, and thus supporting the excellent efficiency of 16.14%. Meanwhile, the influences of the internal spacing of electron and hole in CT state on device performance were explored for further elucidating carrier micro-transport mechanism and instructing further experimental investigation. [ABSTRACT FROM AUTHOR]

Applying materials with complementary optical absorption spectra to construct tandem solar cell can fulfill further improvement of photovoltaic performance, since tandem solar cell can harvest more photons and enhance the open-circuit voltage of the devices. For tandem solar cells, an interconnecting layer (ICL), which physically and electrically connects the front and the rear subcells, is essential to minimize the energy losses. Herein, we adopt MoO 3 /Ag/PFN-Br as interconnecting layer to join front subcell of PBDTBDD:PC 70 BM and rear subcell of PTB7-Th:IEICO-4F for construction the inverted tandem solar cell with structure of ITO/TIPD/PBDTBDD:PC 70 BM/MoO 3 /Ag/PFN-Br/PTB7-Th:IEICO-4F/MoO 3 /Al. The tandem devices demonstrate strong and wide light response in the wavelength between 300 and 1000 nm. A promising power conversion efficiency (PCE) of 9.74% has been achieved with an open circuit voltage ( V oc ) of 1.503 V. The PCE of tandem cell is 41.36% higher than that (6.89%) of front subcell and 27.82% higher than that (7.62%) of rear subcell. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel model to quantify load-carrying capacity of intact double-cage RCPs. • Novel model to quantify residual bearing capacity of corroded RCPs. • FEM models of intact and corroded RCPs set at TEBT condition. • TEBTs for the verification of the calculation and simulation results. Reinforced concrete pipes (RCPs) are widely used as jacking pipes in various infrastructures, such as sewers, tunnels, and pipe galleries. However, owing to the presence of harmful chemicals and microorganisms in the surrounding environment, the pipe gradually corrodes, thereby thinning the pipe wall and lowering the residual bearing capacity (RBC) of the structure. For the daily maintenance of the RCP, the RBC should be evaluated precisely to ascertain the service status of the pipe, and if necessary, timely rehabilitation can be performed to yield the optimal repair outcome and cost efficiency. In this study, quantitative models for RBCs of both intact and corroded RCPs are proposed; these models are based on the plastic collapse failure mode of rigid pipe. Additionally, the impact of uncoordinated deflection between concrete and reinforcement has also been characterised. A series of numerical simulations were developed on the basis of the finite element method (FEM) to evaluate the RBC of corroded RCPs, and the FEM results are consistent with those of the quantitative model. Finally, three-edge bearing (TEB) tests were conducted by incorporating both intact and corroded RCPs. The results of the TEB tests also revealed the reliability of the quantitative model. [ABSTRACT FROM AUTHOR]

Thin metal films can disintegrate into nanoparticles upon thermal annealing. In this work, to obtain silver nanoparticles with controlled morphology, we performed a comparison study on the surface topography evolutions and agglomeration mechanisms of Ag films deposited by magnetron sputtering within-situ annealing (the heating rate is 0.33 °C/s) and ex-situ rapid thermal annealing (the heating rate is 100 °C/s) treatments, respectively. The results confirm that the in-situ annealed Ag films agglomerate via voids nucleation followed by the fractal growth of voids. Moreover, we found that the critical void radius upon which the void growth is favored decreases with increasing the annealing temperature. For the case of rapid annealing, the agglomeration of Ag films follows the grain boundary grooving mechanism due to the rather higher heating rate. Compared with the in-situ heating process, the rapid annealing treatment allows a more uniform size distribution of the nanoparticles. Our findings highlight the key role of heating rate on the size, shape and functionalities of Ag nanoparticles for a wide range of practical applications, and enrich the understandings of the agglomeration mechanism of thin metal films. [ABSTRACT FROM AUTHOR]

In planar heterojunction (PHJ) perovskite solar cells (PerSCs) without mesoporous metal oxide skeleton, there is challenge of formation perovskite film with full coverage to the conductive substrate through solution-process the lead halide precursors. Selecting a lead source with more volatile byproducts is an effective approach to obtain much smoother films with smaller and fewer pinholes. Herein, we demonstrate efficient CH 3 NH 3 PbI 3 /PCBM PHJ PerSCs by using lead acetate (Pb(Ac) 2 ) as lead precursor. The morphology of the perovskite thin films were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively, and the crystalline quality of the perovskite films were investigated by X-ray diffraction (XRD) spectroscopy. Time-resolved photoluminescence (TRPL) was used to investigate the PL lifetime of the perovskite film. The perovskite film derived from Pb(Ac) 2 shows enhanced surface coverage and improved photoluminescence lifetime in comparison with PbI 2 sourced perovskite film. Averaged over 20 individual devices, the power conversion efficiency (PCE) of devices derived from Pb(Ac) 2 reaches 14.81%, much higher than PbI 2 sourced devices by one-step (8.23%) or two-step (10.58%) spin-coating. [ABSTRACT FROM AUTHOR]

• The full-scale tests results of damaged RCPs rehabilitated by centrifugal spraying tech were introduced. • A 3D finite element model of "Damaged Pipe-Repair Lining" structure was established based on CDP and Cohesive Zone models. • Influence rule of related variables on the structure bearing capacity was obtained. • New design method of centrifugal spraying technology for trenchless restoration was elaborated. There has been growing interest in using trenchless technology, especially centrifugal spraying techniques, to renovate the sewer pipe network in China. In this study, a damaged reinforced concrete pipe (RCP) (i.e., 14.7% vertical deformation) with one-meter diameter is rehabilitated by centrifugally spraying on a 50 mm thickness mortar lining. The ultimate (D u) D-load only increased by 2% compared to host pipe's residual strength; however, other pipe properties exhibited improvement. Based on the behavior of two experimental results, finite element models were established, and an innovative pipeline damage quantization model was proposed. Through parameter sensitivity analysis, the effects of interface strength and fracture energy on pipe bearing capacity were studied. It was discovered that interface bonding performance affected the service load of the rehabilitated pipe. From the analysis of pipeline initial state deformation influence on the repaired structure bearing capacity, it was discovered that selecting a reasonable repair time point can effectively improve the functionality of the pipe network and reduce repair costs. An analysis of RCPs structural repair with a vertical deformation larger than 14% revealed that it is difficult to repair damaged pipes only employing mortar spraying. A structural design method based on the service load and ultimate load is presented in this paper. [ABSTRACT FROM AUTHOR]

Abstract: A mesogen-jacketed polymer P-Ct {poly{2,5-bis[(5-tert-butylphenyl)-1,3,4-oxadiazole]styrene}} has been investigated as a host material for IrMDPP [Ir(III)bis(5-methyl-2,3-diphenylpyrazine) (acetyl acetonate)] doped polymer electrophosphorescent device. It was found that the device with P-Ct was more efficient than that with PVK. The maximum luminance and external luminous efficiency can reach 3702cd/m2 and 0.83cd/A, respectively, which were higher than those of device with PVK (1999cd/m2 and 0.68cd/A), which can be partly explained by the more balanced carrier injection and transportation and longer lifetime of excitons in P-Ct–TPD–IrMDPP. It was also found that as the IrMDPP content increased in P-Ct–TPD, the EL spectra color shifts from green-yellow to yellow-orange and were different from PL spectra, which was partly due to the dominating role of direct charge-trapping and recombination in the EL process over the energy-transfer routes. [Copyright &y& Elsevier]

Abstract: A series of novel mesogen-jacketed polymers, poly{2,5-bis[(5-tert-butylphenyl)-1,3,4-oxadiazole]styrene} (P-Ct) and poly{2,5-bis[(5-alkoxyl-phenyl)-1,3,4-oxadiazole]styrene} (P-OCn, n is the number of carbons in the alkoxyl groups, n =6, 8, 10, 12, 14), were incorporated into polymer light-emitting device as the light-emitting layers. All of the polymers had excellent solubility in common organic solvents. The UV and PL spectra for P-Ct were 312 and 400nm while for P-OCn they were around 328 and 420nm in the film. There was no red shift in the PL spectrum of P-Ct after heat treatment which maybe related to the jacketed structure. All of the polymers showed high PL quantum yields in THF solution. From the cyclic voltammetry measurement at room temperature, HOMO levels of the polymers were varied from −5.66 to −6.12eV, LUMO levels were varied from −2.45 to −2.81eV. Furthermore, the influence of the alkoxyl lengths in four different device configurations was compared. For the device configuration c: ITO/PVK/P-OC8/Ca/Ag, the maximum luminance and maximum external quantum efficiency were obtained for P-OC8 which maybe related to the easier electron injection and transport. Efficiency of P-OC8 was not improved with device d which proved the electron transporting characteristics of P-OC8. [Copyright &y& Elsevier]

Abstract: We report the synthesis and structure of a salt (C16H19N2)2[Zn4(C6H5S)10] formed by linking [Zn4(SPh)10]2− cluster with dye molecule trans-4-(4-dimethylamino-styryl)-N-methyl-pyridinium and its luminescent properties as a host emitter in non-doped OLEDs. Devices consisted of ITO/PEDOT (3000rpm)/DMAS–Zn (2000rpm)/BCP (10nm)/Alq3 (20nm)/Mg:Ag (10:1, mass ratio, 150nm)/Ag (10nm), emitted in the red region and the emission is centered at 630nm. The full width at half maximum (FWHM) value of the emission peak is ∼80nm. [Copyright &y& Elsevier]