The rise in interest in two-dimensional (2D) nanomaterials has been notable in recent years. In particular, hexagonal boron nitride (h-BN), recognized as an optimal substrate for enhancing graphene properties, holds promise for electronic applications. However, the widely employed spontaneous Raman microscopy, a gold standard for graphene study, faces strong limitations in h-BN due to its large bandgap and low cross section. In this Letter, high-resolution femto/picosecond coherent anti-Stokes Raman scattering (fs/ps-CARS) spectroscopy is used for hyperspectral imaging of nanometric h-BN layers. Our study establishes that CARS signal effectively enhances Raman signature related to in-plane ring vibrations, thus providing valuable quantitative insights into sample thickness and crystalline quality, also corroborated by additional AFM measurements.

中文翻译：

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使用混合飞秒/皮秒相干反斯托克斯拉曼散射的氮化硼纳米层高光谱显微镜

近年来，人们对二维 (2D) 纳米材料的兴趣日益浓厚。特别是，六方氮化硼（h-BN）被认为是增强石墨烯性能的最佳基材，在电子应用中具有广阔的前景。然而，广泛使用的自发拉曼显微镜（石墨烯研究的黄金标准）由于其带隙大和横截面小而在 h-BN 中面临着很大的局限性。在这封信中，高分辨率飞秒/皮秒相干反斯托克斯拉曼散射 (fs/ps-CARS) 光谱用于纳米 h-BN 层的高光谱成像。我们的研究表明，CARS 信号有效增强了与面内环振动相关的拉曼特征，从而为样品厚度和晶体质量提供了有价值的定量见解，这也得到了额外 AFM 测量的证实。