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The fabrication of the flexible devices with excellent photovoltaic performance and stability is critical for the commercialization of organic solar cells (OSCs). Herein, the conjugated dimer acceptor DY‐TVCl and the non‐conjugated dimer acceptor DY‐3T based on the monomer MY‐BO are synthesized to regulate the molecular glass transition temperatures (Tg) for improving the morphology stability of active layer films. And the crack onset strain values for the blend films based on dimer acceptors are superior than that of small molecule, which are beneficial for the preparation of flexible devices. Accordingly, the binary device based on PM6:DY‐TVCl achieves a maximum power conversion efficiency (PCE) of 18.01%. Meanwhile, the extrapolated T80 (time to reach 80% of initial PCE) lifetimes of the PM6:DY‐TVCl‐based device and PM6:DY‐3T‐based device are 3091 and 2227 h under 1‐sun illumination, respectively, which are better than that of the PM6:MY‐BO‐based device (809 h). Furthermore, the flexible devices based on DY‐TVCl and DY‐3T exhibit the efficiencies of 15.23% and 14.34%, respectively. This work affords a valid approach to improve the stability and mechanical robustness of OSCs, as well as ensuring the reproducibility of organic semiconductors during mass production. [ABSTRACT FROM AUTHOR]

Gallium oxide (Ga2O3), with an ultrawide bandgap corresponding to the deep ultraviolet (DUV) range, has attracted significant attention in optical filter‐free photodetectors. In practical terms, DUV photodetectors employed in extreme conditions, for example, flame detection and space exploration, face the challenges of performance degradation caused by high/low‐temperature transformation. Here, DUV photodetectors are tailored with high durability and stability by one‐step‐grown β‐Ga2O3 films via pulsed laser deposition. A high‐oxygen‐pressure scheme effectively addresses the issue of film‐free deposition at specifically high temperatures, facilitating the formation of polycrystalline high‐resistivity β‐Ga2O3 films. As a result, the devices exhibit outstanding performance, including a low dark current (4.4 pA @30 V), high photoresponsivity (147.36 A W−1), and fast response time (3.1/22.6 ms). Additionally, the photoresponse performance shows minimal degradation at high temperatures up to 300 °C and even improves at low temperatures down to −100 °C, ranking it among the most robust DUV photodetectors. The mechanism of photoresponse, involving the exciton formation, bandgap evolution, carrier‐phonon scatter, etc., is also elucidated in a wide temperature range. This work provides an efficient solution for developing robust Ga2O3 DUV photodetectors with excellent performance for extreme‐condition applications. [ABSTRACT FROM AUTHOR]

The work presented an electrochemical anode method with different electrolyte concentrations and heat posttreatment to control the stoichiometry and structure of Cu2−xS electrocatalysts. X‐ray diffraction, X‐ray photoelectron spectroscopy, and scanning electron microscopy were employed to characterize the composition and morphology, whereas the electrocatalytic activity was evaluated by linear scanning voltammetry and electrochemical impedance spectroscopy. The results showed that the electrochemical method successfully synthesized thin flake‐shaped Cu7S4, which exhibited optimal performance at the electrolyte concentration of 0.45 mol L1 with maximum turnover frequency of 0.786 s−1, maximum mass activity of 0.539 A g−1, minimum charge transfer resistance of 0.156 Ω cm−2, and minimum overpotential of 154 mV at a current density of 10 mA cm−2. In the Cu7S4 structure, Cu2+ and S2− were coordinated in a CuS4 tetrahedral structure, whereas Cu+ and S2− were coordinated in a CuS3 triangular structure. Heat posttreatment could change the stoichiometry from 1.75 to 1.8 and improve the electrochemical performance. In the Cu9S5 structure, the CuS3 triangular structure had disappeared. Under the same conditions, the overvoltage was only 128 mV. [ABSTRACT FROM AUTHOR]