论文标题
级联Brillouin散射是从贵金属粗糙表面的光致发光机制
Cascade Brillouin scattering as a mechanism for photoluminescence from rough surfaces of noble metals
论文作者
论文摘要
在使用等离子体纳米结构作为底物的表面增强的拉曼散射实验中，散射光谱包含通常与光致发光有关的广泛背景。该背景存在于入射波的频率上方和下方。该背景的低频部分类似于等离子体纳米颗粒的散射光谱，而高频部分遵循吉布斯分布。我们开发了一种理论，该理论从统一的角度解释了光致发光光谱的高频和低频部分中的实验观察到的特征。我们表明，光致发光归因于在等离子体共振条件下金属声子在入射波中的级联发光散射。该理论与我们在背景的整个频率范围内的测量非常吻合。
In surface-enhanced Raman scattering experiments that use plasmonic nanostructures as substrates, the scattering spectrum contains a broad background usually associated with photoluminescence. This background exists above and below the frequency of the incident wave. The low-frequency part of this background is similar to the scattering spectrum of a plasmon nanoparticle, while the high-frequency part follows the Gibbs distribution. We develop a theory that explains experimentally observed features in both the high- and low-frequency parts of the photoluminescence spectrum from a unified point of view. We show that photoluminescence is attributed to the cascade Brillouin scattering of the incident wave by metal phonons under the plasmon resonance conditions. The theory is in good agreement with our measurements over the entire frequency range of the background.
