Observation of Core Phonon in Electron–Phonon Coupling in Au25 Nanoclusters
| Autor: | Rongchao Jin, Zhongyu Liu, Yingwei Li, Wonyong Shin |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Work (thermodynamics)
Materials science Condensed matter physics Icosahedral symmetry Liquid helium Phonon 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Nanoclusters law.invention Core (optical fiber) Condensed Matter::Materials Science Atomic electron transition law Condensed Matter::Superconductivity General Materials Science Physical and Theoretical Chemistry 0210 nano-technology Absorption (electromagnetic radiation) |
| Zdroj: | The Journal of Physical Chemistry Letters. 12:1690-1695 |
| ISSN: | 1948-7185 |
| Popis: | Temperature-dependent optical properties are of paramount importance for fundamentally understanding the electron-phonon interactions and phonon modes in atomically precise nanocluster materials. In this work, low-temperature optical absorption spectra of the icosahedral [Au25(SR)18]- nanocluster are measured from room temperature down to liquid helium temperature by adopting a thin-film-based technique. The thin-film measurement is further compared with results from the previous solution-based method. Interestingly, the previously missing core phonon is revealed by a quantitative analysis of the film data through peak deconvolution and fitting of the temperature trend with a theoretical model. The two lowest-energy absorption peaks (at 1.6 and 1.8 eV) of Au25 are determined to couple with the staple-shell phonon (average energy ∼350 cm-1) in the solution state, but in the solid state these electronic transitions couple with the core phonon (average energy ∼180 cm-1). The suppression of the staple-shell phonon in the solid state is attributed to the intracluster and cluster-matrix interactions. |
| Databáze: | OpenAIRE |
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