Two-dimensional systems such as surfaces and molecular monolayers exhibit a multitude of intriguing phases and complex transitions. Ultrafast structural probing of such systems offers direct time-domain information on internal interactions and couplings to a substrate or bulk support. We have developed ultrafast low-energy electron diffraction and investigate in transmission the structural relaxation in a polymer/graphene bilayer system excited out of equilibrium. The laser-pump/electron-probe scheme resolves the ultrafast melting of a polymer superstructure consisting of folded-chain crystals registered to a free-standing graphene substrate. We extract the time scales of energy transfer across the bilayer interface, the loss of superstructure order, and the appearance of an amorphous phase with short-range correlations. The high surface sensitivity makes this experimental approach suitable for numerous problems in ultrafast surface science.
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http://dx.doi.org/10.1126/science.1250658 | DOI Listing |
The interaction between ultrafast, tightly focused lasers and materials has garnered significant interest owing to its distinctive properties. In this study, we present a versatile methodology for the fabrication of tunable plasmonic nanostructures by employing a disordered gold nanoisland-dielectric-metal configuration, achieved through femtosecond laser printing. By reshaping the gold nanoislands and reconfiguring them into nanograting-like structures, the orientation of these nanostructures is influenced by the polarization of the femtosecond laser light, leading to controllable plasmon resonance and polarization-sensitive color display.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Terahertz Research Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.
Low-dimensional materials (LDMs) with unique electromagnetic properties and diverse local phenomena have garnered significant interest, particularly for their low-energy responses within the terahertz (THz) range. Achieving deep subwavelength resolution, THz nanoscopy offers a promising route to investigate LDMs at the nanoscale. Steady-state THz nanoscopy has been demonstrated as a powerful tool for investigating light-matter interactions across boundaries and interfaces, enabling insights into physical phenomena such as localized collective oscillations, quantum confinement of quasiparticles, and metal-to-insulator phase transitions (MITs).
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Department of Mechanical Engineering and Technology Management, Norwegian University of Life Sciences, N-1433 AS, Norway.
Hybrid molecular ferroelectrics with orientationally disordered mesophases offer significant promise as lead-free alternatives to traditional inorganic ferroelectrics owing to properties such as room temperature ferroelectricity, low-energy synthesis, malleability, and potential for multiaxial polarization. The ferroelectric molecular salt HdabcoClO is of particular interest due to its ultrafast ferroelectric room-temperature switching. However, so far, there is limited understanding of the nature of dynamical disorder arising in these compounds.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemistry, Institute of Biomimetic Materials & Chemistry, Anhui Engineering Laboratory of Biomimetic Materials, Division of Nanomaterials & Chemistry, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China.
The development of viscous-crude oil and water separation technology is important for overcoming pollution caused by oil spills. Although some separators responding to light, electric, and temperature have been proposed, their poor structural homogeneity and inferior controllability, together with weak capillary forces, hinder the rapid salvage of viscous crude oil. Herein, a Joule-heated hydrophobic porous oil/water separator is reported, which has advantages of low energy consumption (169.
View Article and Find Full Text PDFNatl Sci Rev
January 2025
State Key Laboratory of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, Renewable Energy Conversion and Storage Center (RECAST), Tianjin Key Laboratory of Functional Polymer Materials, Nankai University, Tianjin 300071, China.
It remains challenging to design efficient bifunctional semiconductor materials in organic photovoltaic and photodetector devices. Here, we report a butterfly-shaped molecule, named WD-6, which exhibits low energy disorder and small reorganization energy due to its enhanced molecular rigidity and unique assembly with strong intermolecular interaction. The binary photovoltaic device based on PM6:WD-6 achieved an efficiency of 18.
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