Editorial: Polymer Solar Cells: Molecular Design and Microstructure Control

[No abstract available

Realizing 18.03% efficiency and good junction characteristics in organic solar cells via hydrogen-bonding interaction between glucose and ZnO electron transport layers

Electron transport layers (ETLs) with excellent electron extraction capability are essential for realizing high efficiency in organic solar cells (OSCs). A sol-gel-processed ZnO ETL is widely used in OSCs due to its high mobility and suitable work function. However, the existence of defects usually results in low photovoltaic performance during the operation of OSCs. In this work, glucose (Gl) was used to passivate free OH traps via hydrogen-bonding interaction and formed ZnO/Gl ETLs with ZnO, which exhibited improved electron extraction capability and reduced trap defect density. Thus, a champion efficiency of 18.03% was obtained in a PM6:Y6 light absorber-based cell, which is >11% higher than that of the reference cell (16.15%) with a pristine ZnO ETL. Impressive enhancements by >11% were also observed in different fullerene and non-fullerene light absorber-based cells relative to that of the reference cell. This study demonstrates a new strategy to design ETLs for realizing high efficiency in OSCs

Improving Performance of All-Polymer Solar Cells Through Backbone Engineering of Both Donors and Acceptors

All-polymer solar cells (APSCs), composed of semiconducting donor and acceptor polymers, have attracted considerable attention due to their unique advantages compared to polymer-fullerene-based devices in terms of enhanced light absorption and morphological stability. To improve the performance of APSCs, the morphology of the active layer must be optimized. By employing a random copolymerization strategy to control the regularity of the backbone of the donor polymers (PTAZ-TPDx) and acceptor polymers (PNDI-Tx) the morphology can be systematically optimized by tuning the polymer packing and crystallinity. To minimize effects of molecular weight, both donor and acceptor polymers have number-average molecular weights in narrow ranges. Experimental and coarse-grained modeling results disclose that systematic backbone engineering greatly affects the polymer crystallinity and ultimately the phase separation and morphology of the all-polymer blends. Decreasing the backbone regularity of either the donor or the acceptor polymer reduces the local crystallinity of the individual phase in blend films, affording reduced short-circuit current densities and fill factors. This two-dimensional crystallinity optimization strategy locates a PCE maximum at highest crystallinity for both donor and acceptor polymers. Overall, this study demonstrates that proper control of both donor and acceptor polymer crystallinity simultaneously is essential to optimize APSC performance

Nanoarchitectured Array Electrodes for Rechargeable Lithium- and Sodium-Ion Batteries

Rechargeable ion batteries have contributed immensely to shaping the modern world and been seriously considered for the efficient storage and utilization of intermittent renewable energies. To fulfill their potential in the future market, superior battery performance of high capacity, great rate capability, and long lifespan is undoubtedly required. In the past decade, along with discovering new electrode materials, the focus has been shifting more and more toward rational electrode designs because the performance is intimately connected to the electrode architectures, particularly their designs at the nanoscale that can alleviate the reliance on the materials' intrinsic nature. The utilization of nanoarchitectured arrays in the design of electrodes has been proven to significantly improve the battery performance. A comprehensive summary of the structural features and fabrications of the nanoarchitectured array electrodes is provided, and some of the latest achievements in the area of both lithium‐ and sodium‐ion batteries are highlighted. Finally, future challenges and opportunities that would allow further development of such advanced electrode configuration are discussed

Thermal Decomposition Behavior and Thermal Safety of Nitrocellulose with Different Shape CuO and Al/CuO Nanothermites

Bamboo leaf-like CuO(b) and flaky-shaped CuO(f) were prepared by the hydrothermal method, and then combined with Al nanoparticles to form Al/CuO(b) and Al/CuO(f) by the ultrasonic dispersion method. The phase, composition, morphology, and structure of the composites were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy scattering spectrometer (EDS). The compatibility of CuO, Al/CuO and nitrocellulose (NC) was evaluated by differential scanning calorimetry (DSC). The effects of CuO and Al/CuO on the thermal decomposition of NC were also studied. The results show that the thermal decomposition reactions of CuO-NC composite, Al/CuO-NC composite, and NC follow the same kinetic mechanism of Avrami-Erofeev equation. In the cases of CuO and Al/CuO, they could promote the O-NO2 bond cleavage and secondary autocatalytic reaction in condensed phase. The effects of these catalysts have some difference in modifying the thermolysis process of NC due to the microstructures of CuO and the addition of Al nanopowders. Furthermore, the presence of Al/CuO(f) can make the Al/CuO(f)-NC composite easier to ignite, whereas the composites have strong resistance to high temperature. Compatibility and thermal safety analysis showed that the Al/CuO had good compatibility with NC and it could be used safely. This contribution suggests that CuO and Al/CuO played key roles in accelerating the thermal decomposition of NC

Investigation of Flame Structures of Double-Base Propellant and Modified Double-Base Propellant Containing Nitramine Using OH-PLIF and Kinetic Simulation

The combustion behavior of various propellant samples, including double-base propellants, pressed nitramine powders, and modified double-base propellants containing nitramine, was examined using OH-PLIF technology. The combustion process took place within a combustion chamber, and images capturing the flame at the moment of stable combustion were selected for further analysis. The distribution and production rate of OH radicals in both the double-base propellant and the nitramine-modified double-base propellant were simulated using Chemkin-17.0 software. The outcomes from both the experimental and simulation studies revealed that the concentration of OH radicals increased with a higher content of NG in the double-base propellant. In the modified double-base propellant containing RDX, the OH radical concentration decreased as the RDX content increased, with these tendencies of change aligning closely with the simulation results

RZ Pyx: A special short period detached massive binary with two cool stellar companions in a quadruple system

RZ Pyx is one of a small group of short-period B-type eclipsing binaries with an orbital period of 0.656 days. Several new CCD times of light minimum of RZ Pyx were obtained. Together with all available photoelectric and CCD times of light minimum, the changes of the orbital period are investigated for the first time. Meanwhile, previously published light curves are reanalyzed with the Wilson–Devinney code. Based on the analysis of the O–C diagram, two cyclic variations with periods of 37.1 years and 9.7 years are discovered superimposed on a continuous increase at a rate of dP/dt=+0.32×10−7 day yr−1. The light curve solutions suggest that RZ Pyx is a marginal detached binary system where both components do not overfill their respective Roche lobes. The fill-out factors of the primary and the secondary component are 95.5(±0.8)% and 99.1(±1.9)%, respectively, revealing that the secondary is nearly filling its Roche lobe. This may indicate that RZ Pyx has undergone a mass-transferring evolutionary stage and it is on the marginal detached stage temporarily. The long-term increase in the orbital period could be explained by the enhanced mass loss by stellar winds of the two detached massive components. Since the two binary components are early-type stars, the two cyclic oscillations could be plausibly interpreted as the results of the light travel-time effect caused by the presence of two additional companions. It is estimated that the masses of the two additional bodies are no less than 0.36M⊙ and 0.21M⊙, respectively. The two cool stellar companions are orbiting the central binary at orbital separations of 23.1 and 9.5 au in a quadruple stellar system. Both the marginal detached configuration and the presence of two cool stellar companions make RZ Pyx a very interesting binary system for further investigations.Fil: Ergang, Zhao. Chinese Academy of Sciences; República de ChinaFil: Shengbang, Qian. Chinese Academy of Sciences; República de ChinaFil: Linjia, Li. Chinese Academy of Sciences; República de ChinaFil: Fernandez Lajus, Eduardo Eusebio. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Jia, Zhang. Chinese Academy of Sciences; República de ChinaFil: Xiangdong, Shi. Chinese Academy of Sciences; República de Chin

Effect of molybdenum tailings aggregate on mechanical properties of engineered cementitious composites and stirrup-confined ECC stub columns

Engineered cementitious composites (ECC) exhibit behaviors of multiple cracking and strain-hardening compared to ordinary concrete. However, the use of ultrafine silica sand (S) to produce ECC results in increased cost and environmental overload. This study was to develop an eco-friendly and cheaper ECC by incorporating different replacement ratios of industrial byproduct molybdenum tailings (MT). The mechanical properties of ECC with MT were evaluated. Based on industrial computer technology, nuclear magnetic resonance, and scanning electron microscope techniques, the three-dimensional spatial distribution and fluid distribution of pores and the microstructure of the ECC were investigated, respectively. The mechanical properties of stirrup-confined ECC stub columns were also investigated. Results indicated that the ECC incorporating 25% MT exhibited the best mechanical properties, in which the tensile strength (f t) increased by 32.16% and exhibited well strain-hardening behaviors. Under a 25% MT replacement ratio, ECC had the lowest porosity and good interfacial transition zone, and bonding interface between polyvinyl alcohol (PVA) fiber (PF) and matrix. Moreover, the stirrup-confined ECC stub column with 25% MT can ensure better both the peak stress (f cc) and peak strain (ε cc). The assessment of environmental impact and cost further indicated that the incorporation of MT to prepare ECC is a promising method