Rani Chanchal, Tanwar Manushree, Kandpal Suchita, Ghosh Tanushree, Bansal Love, Kumar Rajesh
Materials and Device Laboratory, Department of Physics, Indian Institute of Technology Indore, Simrol 453552, India.
J Phys Chem Lett. 2022 Jun 7:5232-5239. doi: 10.1021/acs.jpclett.2c01248.
A nonlinear Fano interaction has been reported here which is manifest in terms of a parabolic temperature-dependent phonon decay process observable in terms of a Raman spectral parameter. Temperature-dependent Raman spectroscopic studies have been carried out on heavily and moderately doped crystalline silicon to investigate the behavior of anharmonic phonon decay in semiconductor systems where Fano interactions are present inherently. Systematic study reveals that in heavily doped systems an interferon-mediated decay route exists for cold phonons present at lower temperatures (<475 K) where Fano coupling is stronger and dominates over the typical multiple-phonon decay process. On the other hand, the anharmonic phonon decay remains the predominant process at higher temperatures irrespective of the doping level. Temperature-dependent phonon self-energy has been calculated using experimentally observed Raman line-shape parameters to validate the fact that the nonlinear decay of phonons through interferon mediation is a thermodynamically favorable process at low temperatures.
本文报道了一种非线性法诺相互作用，它表现为一种与温度相关的抛物线型声子衰变过程，可通过拉曼光谱参数观测到。对重掺杂和中掺杂的晶体硅进行了与温度相关的拉曼光谱研究，以研究本征存在法诺相互作用的半导体系统中非谐声子衰变的行为。系统研究表明，在重掺杂系统中，对于低温（<475K）下存在的冷声子，存在一种干扰素介导的衰变途径，此时法诺耦合更强，且在典型的多声子衰变过程中占主导地位。另一方面，无论掺杂水平如何，非谐声子衰变在较高温度下仍然是主要过程。利用实验观测到的拉曼线形参数计算了与温度相关的声子自能，以验证声子通过干扰素介导的非线性衰变在低温下是一个热力学有利过程这一事实。
