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Stretchable electrodes are critical to the development of advanced technologies such as human–machine interaction, flexible sensing, and wearable power supply, making them of significant research value. However, the current preparation methods for high‐performance stretchable electrodes are complex and inefficient, posing challenges for their large‐scale application in the realm of flexible wearables. To address this need, a straightforward and efficient embedding strategy is reported for fabricating stretchable silver nanowire/thermoplastic elastomer composite electrodes (referred to as Strem‐AT) utilizing the viscoelasticity and outstanding mechanical properties of polymer elastomers to achieve outstanding extensibility, conductivity, and a smooth surface. These electrodes exhibit excellent tensile behavior, low surface roughness, and stable electrical properties, enabling their successful integration into stretchable sensors and intrinsically stretchable organic photovoltaic cells (IS‐OPV). When applied to human skin joints for motion detection, the sensor demonstrates remarkable stretchability and stable signal output. Importantly, the all‐polymer IS‐OPV exhibits a top‐notch power conversion efficiency (PCE) of >12.5% and a PCE80% strain exceeding 50%. Furthermore, even after subjecting high‐strain stretching at 50% for 1000 cycles, the IS‐OPV can retain 76% of the initial PCE. This study presents a multifunctional stretchable electrode with high repeatability and easy‐to‐scale fabrication in wearable sensors and photovoltaics. [ABSTRACT FROM AUTHOR]

Intrinsically stretchable organic photovoltaic cells (OPVs) have garnered significant attention as crucial devices for powering next‐generation wearable electronics. Despite the rapid power conversion efficiency gains in champion OPVs, their brittle stretchability has failed to meet the demands of the Internet of Things era, severely hindering further development and practical applications. In this regard, a new dual‐donor polymer blending strategy is demonstrated for constructing intrinsically stretchable OPVs by designing a novel high‐molecular–weight conjugated polymer PM6‐HD. This PM6 derivative featuring long alkyl chains can reach a sufficiently high molecular weight and thus exhibits a high fracture strain exceeding 90%, which is ≈12 times higher than the benchmark PM6. Synergistic optimization of mechanical properties and photovoltaic performance in polymer:small molecule and all‐polymer systems constructed from the physical blends of PM6 and PM6‐HD is achieved. Crucially, the resulting intrinsically stretchable OPV demonstrates excellent stretchability and stability, with a record PCE80% strain of 50.3% and the efficiency retention of above 80% even after 1000 cycles of cyclic stretching at high strains. This work contributes to the advancement of intrinsically stretchable OPV technology and opens up new possibilities for its integration into wearable electronic devices. [ABSTRACT FROM AUTHOR]

The progress of stretchable and wearable photovoltaics relies heavily on intrinsically stretchable active layer films. Nevertheless, there is a paucity of research clarifying the connections between their microstructure, performance, and their adaptation to large strain in polymer electronic films. The current study utilizes multiple synchrotron X‐ray scattering methods to collectively examine the correlations between morphology and stretchability, as well as the microstructural evolution induced by stretching in three sample cases of highly stretchable ternary blend films. These blends contain over 30% by weight of a polymer elastomer, such as styrene‐ethylene‐butylene‐styrene block copolymer, integrated into the high‐performance polymer:nonfullerene small molecule mixture. Specifically, the real‐time microstructural changes of these durable organic photovoltaic films with elastomers are monitored when subjected to tensile stretching through in situ synchrotron X‐ray scattering. The experiments demonstrate that polymeric elastomers can effectively lower the degree of crystallinity in films and deform the crystallites of semiconductor molecules. The elastomeric component aids in stress dispersion during stretching, thereby improving the microstructural durability of blend films. This study provides new recommendations for advancing stretchable organic optoelectronic devices. [ABSTRACT FROM AUTHOR]

The power conversion efficiency of organic photovoltaics (OPVs) has witnessed continuous breakthroughs in the past few years, mostly benefiting from the extensive use of a facile ternary blending strategy by blending the host polymer donor:small molecule acceptor mixture with a second small molecule acceptor. Nevertheless, this rather general strategy used in the well‐known PM6 systems fails in constructing high‐performance P3HT‐based ternary OPVs. As a result, the efficiencies of all resulting ternary blends based on a benchmark host P3HT:ZY‐4Cl and a second acceptor are no more than 8%. Employing the mutual miscibility of the binary blends as a guide to screen the second acceptor, here we were able to break the longstanding 10%‐efficiency barrier of ternary OPVs based on P3HT and dual nonfullerene acceptors. With this rational approach, we identified a multifunctional small molecule acceptor BTP‐2Br to simultaneously improve the photovoltaic performance in both P3HT and PM6‐based ternary OPVs. Attractively, the P3HT:ZY‐4Cl:BTP‐2Br ternary blend exhibited a record‐breaking efficiency of 11.41% for P3HT‐based OPVs. This is the first‐ever report that over 11% efficiency is achieved for P3HT‐based ternary OPVs. Importantly, the study helps the community to rely less on trial‐and‐error methods for constructing ternary solar cells. [ABSTRACT FROM AUTHOR]

In this paper, a numerical simulation method based on the camshaft casting process and crack expansion was proposed to study the propagation characteristics of casting hot cracks. The dynamic visualisation process of hot crack growth indicates that the formation of hot tear is dominated by opening mode cracks. And during the propagation process, the equivalent stress intensity factor at the crack front first decreases and then increases. Furthermore, the propagation characteristics of the crack under different hot tear initiation conditions were studied by this method. The results reveal that the expansion ability of a hot crack is affected by the equilibrium solidification scale, solidification sequence, and solidification path of the casting. Finally, using the microscopic morphology of the cracks, the semi-quantitative analysis of the elements illustrates that the carbon content decreases sharply at the crack formation site, while manganese and sulphur are relatively rich. [ABSTRACT FROM AUTHOR]

The emerging solution‐based solar cells and photodetectors have gained worldwide research interest over the past decades. Hole transport materials (HTMs) have greatly advanced the progress of these solution‐based electronics. Nevertheless, developing low‐cost and efficient HTMs is far from satisfactory. In this contribution, poly(3‐pentylthiophene) (P3PT) is introduced as a facile, low‐cost, and versatile dopant‐free polymer HTM for both quantum dot (QD) and perovskite electronic devices. Compared to the broadly used poly(3‐hexylthiophene), P3PT presents the reduced molecular aggregation and preferential face‐on orientation, which can markedly enhance the hole‐carrier transport in optoelectronic devices. Accordingly, P3PT can deliver the substantial improvement of photovoltaic performance from ∼8.6% to ∼9.5% for QD/polythiophene solar cells and from ∼16% to ∼18.8% for perovskite/polythiophene solar cells, which are both among the topmost values in the corresponding fields. Furthermore, P3PT HTMs can also significantly enhance the photodetection performance of QD and perovskite photodetectors by a factor of ∼3, indicating its great application potential in a variety of emerging optoelectronics. [ABSTRACT FROM AUTHOR]

To improve the comprehensive mechanical properties of Mg-15Al magnesium alloy, different amounts (from 0 to 4.0wt.%) of Nd were added to the alloy and six Mg-15Al-xNd alloys were prepared by metal mould casting. The effect of Nd content on microstructure of the alloys was investigated by means of OM, SEM, EDS, TEM, and XRD. The tensile properties were tested at room temperature (RT) and high temperature (473 K). The results indicate that the primary α-Mg dendrite is significantly refined with the addition of Nd. The best refinement is reached at 1.0wt.% Nd content and the average dendrite arm spacing decreases from 80-100 μm (without Nd addition) to ~20 μm. A further increase in Nd content leads to the coarsening of the primary α-Mg dendrite. The addition of Nd improves the tensile properties of Mg-15Al both at RT and 473 K. The Mg-15Al alloy containing 1.0wt.% Nd exhibits the best tensile properties. Compared with the alloy without Nd, the yield and ultimate tensile strength of the Mg-15Al-1.0Nd alloy at RT increase from 132.3 to 148.6 MPa and 152.3 to 189.6 MPa, increase by 12.3% and 24.5%, respectively; and the elongation at RT increases from 0.05 % to 1.24%. The yield and tensile strength of the alloy at 473 K increase from 97.9 to 115.3 MPa and 121.6 to 140.1 MPa, increase by 15.2% and 20%, respectively. Further increment of Nd content to 1.5wt.% degrades the tensile properties, which is ascribed to grain coarsening and growth of the Al-Nd phase.