In this study, the polarization-resolved Raman spectra of b-AsP flakes with varying arsenic concentration (x = 0, 0.4, and 0.8) are systematically investigated. A clear polarization dependence is observed in the Raman intensity of all the P-P, As-P, and As-As modes and confirmed by the first-principles calculations. The observed angle-dependence can be related to the structure of the Raman tensors of each peak. In particular, the Raman intensities corresponding to As-P vibration modes are studied in detail. The out of plane As-P mode ( is clearly identified, but the butterfly-shaped behavior observed in the polar plot around 350 cm is interpreted as the combination of the two in-plane vibrations, one along the armchair and the other along the zigzag direction. This work allows unambiguous assignment of the , , and modes of the As-P vibrational modes and the importance of the consideration of the superposition of the in-plane and modes. Such study can be utilized to further characterize the anisotropic structural properties and analyze the local distribution of the As and P in alloys which will play key roles in electronic and optical properties. This methodology can be further extended to alloyed two-dimensional material systems with in-plane anisotropy in general.

中文翻译：

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层状 b-AsxPx-1 合金的角分辨偏振拉曼研究：As-P 振动模式的识别

在本研究中，系统研究了不同砷浓度（x = 0、0.4 和 0.8）的 b-AsP 薄片的偏振分辨拉曼光谱。在所有 PP、As-P 和 As-As 模式的拉曼强度中观察到明显的偏振依赖性，并通过第一性原理计算得到证实。观察到的角度依赖性可以与每个峰的拉曼张量的结构相关。特别是，详细研究了 As-P 振动模式对应的拉曼强度。面外 As-P 模式（已清晰识别，但在 350 cm 左右的极坐标图中观察到的蝴蝶形行为被解释为两个面内振动的组合，一个沿着扶手椅，另一个沿着锯齿形这项工作允许明确分配 As-P 振动模式的 、 和 模式，以及考虑面内和模式叠加的重要性。此类研究可用于进一步表征各向异性结构特性和结构。分析合金中 As 和 P 的局部分布，这将在电子和光学性能中发挥关键作用，该方法可以进一步扩展到具有面内各向异性的合金二维材料系统。