Lee Seong-Yeon, Yee Ki-Ju
Department of Physics and Institute of Quantum Systems, Chungnam National University, Daejeon 34134, Korea.
Nanomaterials (Basel). 2021 May 1;11(5):1202. doi: 10.3390/nano11051202.
Black phosphorus (BP) has attracted great attention due to its layer-tuned direct bandgap, in-plane anisotropic properties, and novel optoelectronic applications. In this work, the anisotropic characteristics of BP crystal in terms of the Raman tensor and birefringence are studied by investigating polarization dependence in both the generation and detection of A mode coherent phonons. While the generated coherent phonons exhibit the typical linear dichroism of BP crystal, the detection process is found here to be influenced by anisotropic multiple thin film interference, showing wavelength and sample thickness sensitive behaviors. We additionally find that the A and A optical phonons decay into lower frequency acoustic phonons through the temperature-dependent anharmonic process.
黑磷（BP）因其层调谐直接带隙、面内各向异性特性以及新型光电应用而备受关注。在这项工作中，通过研究A模相干声子产生和探测过程中的偏振依赖性，对黑磷晶体在拉曼张量和双折射方面的各向异性特性进行了研究。虽然所产生的相干声子表现出黑磷晶体典型的线性二向色性，但在此发现探测过程受各向异性多薄膜干涉影响，呈现出对波长和样品厚度敏感的行为。我们还发现，A光学声子和A光学声子通过与温度相关的非谐过程衰变为低频声学声子。
