AI 中文总结
研究分子-金属纳米腔内电荷转移共振能量条件，利用含联苯硫醇衍生物单层的纳米颗粒-镜面结，结合多种光谱和理论计算，定量评估相关能量关系，为探测和工程化电荷转移过程建立框架并提供机理见解。
AI 中文摘要
界面电荷转移过程在等离子体增强光谱中起着关键作用，但分子-金属纳米腔内电荷转移共振的能量条件仍知之甚少。本文利用包含系统工程化联苯硫醇衍生物单层的等离子体纳米颗粒-镜面结，研究前沿轨道排列如何影响化学增强机制。通过表面增强拉曼散射（SERS）、振动和频产生（vSFG）光谱以及密度泛函理论计算，研究了一系列具有广泛电子调谐受体状态的分子库。结合不同激发波长以及可控的衬底成分和分子电子结构变化，定量评估了等离子体增强电荷转移激发与分子轨道排列之间的能量关系。结果表明，拉曼散射的电荷转移增强受明确的界面共振条件支配，该条件取决于衬底功函数和激发能量。通过纳米腔增强的vSFG进一步探测了分子-金属系统的一个子集，发现与SERS中相同的共振条件，与预期一致。这些发现为探测和工程化等离子体分子结中的电荷转移过程建立了一个实验上可及的框架，并为分子等离子体、电荷载流子光物理和纳米级界面光谱提供了机理见解。
英文摘要
Interfacial charge-transfer processes play a critical role in plasmon-enhanced spectroscopy, yet the energetic conditions governing charge-transfer resonance within molecule-metal nanocavities remain poorly understood. Here, plasmonic nanoparticle-on-mirror junctions incorporating systematically engineered biphenylthiol derivatives monolayers were used to investigate how frontier orbital alignment influences chemical enhancement mechanisms. A molecular library spanning a broad range of electronically tuned acceptor states was examined using surface-enhanced Raman scattering (SERS), vibrational sum frequency generation (vSFG) spectroscopy, and density functional theory calculations. By combining different excitation wavelengths with controlled variation of substrate composition and molecular electronic structure, the energetic relationship between plasmon-enhanced charge transfer excitation and molecular orbital alignment was quantitatively evaluated. The results reveal that charge-transfer enhancement of Raman scattering is governed by a well-defined interfacial resonance condition dependent on substrate work function and excitation energy. We further probe a subset of molecular-metal systems by nanocavity-enhanced vSFG and identify the same resonance conditions as in SERS, consistent with expectations. These findings establish an experimentally accessible framework for probing and engineering charge-transfer processes in plasmonic molecular junctions and provide mechanistic insight relevant to molecular plasmonics, charge carrier photophysics, and nanoscale interfacial spectroscopy.
