Multiple parameters of nanocomposite Si/Sb₈₀Te₂₀ multilayer films are possibly optimized simultaneously to satisfy the development of ideal phase-change memory devices by adjusting chemical composition and physical structure of multilayer films. The crystallization and structure of the films are studied by coherent phonon spectroscopy. Laser irradiation power dependence of coherent optical phonon spectroscopy reveals laser-induced crystallization of the amorphous multilayer film, while coherent acoustic phonon spectroscopy reveals the presence of folded acoustic phonons which suggests a good periodic structure of the multilayer films. Laser irradiation-induced crystallization shows applicable potentials of the multilayer films in optical phase change storage.
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http://dx.doi.org/10.1364/OE.19.022684 | DOI Listing |
J Phys Chem Lett
January 2025
Institute of Bioproducts and Paper Technology, Graz University of Technologyy, Inffeldgasse 23, 8010 Graz, Austria.
The mechanical properties of metal-organic frameworks (MOFs) are of high fundamental and practical relevance. A particularly intriguing technique for determining anisotropic elastic tensors is Brillouin scattering, which so far has rarely been used for highly complex materials like MOFs. In the present contribution, we apply this technique to study a newly synthesized MOF-type material, referred to as GUT2.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Hunan Key Laboratory of Super-Microstructure and Ultrafast Process, School of Physics, Central South University, Changsha 410083, China.
Two-dimensional (2D) layered materials have received much attention due to the unique properties stemming from their van der Waals (vdW) interactions, quantum confinement, and many-body interactions of quasi-particles, which drive their exotic optical and electronic properties, making them critical in many applications. Here, we review our past years' findings, focusing on many-body interactions in 2D layered materials, including phonon anharmonicity, electron-phonon coupling (), exciton dynamics, and phonon anisotropy based on temperature (polarization)-dependent Raman spectroscopy and Photoluminescence (PL). Our review sheds light on the role of quasi-particles in tuning the material properties, which could help optimize 2D materials for future applications in electronic and optoelectronic devices.
View Article and Find Full Text PDFACS Nano
January 2025
Beijing Academy of Quantum Information Sciences, Beijing 100193, P. R. China.
The quantum-well-like two-dimensional lead-halide perovskites exhibit strongly confined excitons due to the quantum confinement and reduced dielectric screening effect, which feature intriguing excitonic effects. The ionic nature of the perovskite crystal and the "softness" of the lattice induce the complex lattice dynamics. There are still open questions about how the soft lattices decorate the nature of excitons in these hybrid materials.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
DICP: Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, CHINA.
Broad-temperature optical thermometry necessitates materials with exceptional sensitivity and stability across varied thermal conditions, presenting challenges for conventional systems. Here, we report a lead-free, vacancy-ordered perovskite Cs2TeCl6, that achieves precise temperature sensing through a novel combination of self-trapped excitons (STEs) photoluminescence (PL) lifetime modulation and unprecedented fifth-order phonon anharmonicity. The STEs PL lifetime demonstrates a highly temperature-sensitive response from 200 to 300 K, ideal for low-to-intermediate thermal sensing.
View Article and Find Full Text PDFSmall Methods
January 2025
NEST, Istituto Nanoscienze - CNR and Scuola Normale Superiore, Pisa, I-56127, Italy.
A ground-breaking graphene-based biosensor designed for label-free detection of immunoglobulin M (IgM) achieving a remarkable concentration of 100 zeptomolar (10 m), is reported. The sensor is a two-terminal device and incorporates a millimeter-wide gold interface, bio-functionalized with ≈10 anti-IgM antibodies and capacitively coupled to a bare graphene electrode through a water-soaked paper strip. In this configuration, few affinity binding events trigger a collective electrostatic reorganization of the protein layer, leading to an extended surface potential (SP) shift of the biofunctionalized Au surface.
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