Yogi Priyanka, Mishra Suryakant, Saxena Shailendra K, Kumar Vivek, Kumar Rajesh
Material Research Laboratory, Discipline of Physics & MEMS, Indian Institute of Technology Indore , Simrol 453552, India.
Department of Physics, National Institute of Technology Meghalaya , Laitumkhrah, Shillong 793003, Meghalaya, India.
J Phys Chem Lett. 2016 Dec 15;7(24):5291-5296. doi: 10.1021/acs.jpclett.6b02090. Epub 2016 Dec 7.
Size-dependent asymmetric low-frequency Raman line shapes have been observed from silicon (Si) nanostructures (NSs) due to a quantum confinement effect. The acoustic phonons in Si NSs interact with an intraband quasi-continuum to give rise to Fano interaction in the low-frequency range. The experimental asymmetric Raman line shape has been explained by developing a theoretical model that incorporates the quantum-confined phonons interacting with an intraband quasi-continuum available in Si NSs as a result of discretization of energy levels with unequal separation. We discover that a phenomenon similar to Brillouin scattering is possible at the nanoscale in the low-frequency regime and thus may be called "Fano scattering" in general. A method has been proposed to extract information about nonradiative transitions from the Fano scattering data where these nonradiative transitions are involved as an intraband quasi-continuum in modulation with discrete acoustic phonons.
由于量子限制效应，在硅（Si）纳米结构（NSs）中观察到了尺寸依赖的不对称低频拉曼线形。Si NSs中的声子与带内准连续体相互作用，在低频范围内产生法诺相互作用。通过建立一个理论模型来解释实验中的不对称拉曼线形，该模型将量子限制声子与由于能级离散化且间距不等而在Si NSs中可用的带内准连续体相互作用考虑在内。我们发现，在纳米尺度的低频区域可能存在一种类似于布里渊散射的现象，因此一般可称为“法诺散射”。已经提出了一种从法诺散射数据中提取有关非辐射跃迁信息的方法，其中这些非辐射跃迁作为带内准连续体参与与离散声子的调制。
