多层堆垛黑磷烯的超低频拉曼光谱研究

As a novel two-dimensional anisotropic material, black phosphorus (BP) has direct adjustable band gap with high mobility, which makes up for the shortcomings of graphene and transition metal dichalcogenides, and therefore has broad application potential. The electronic structure of multilayer two-dimensional materials is tightly related to their layer stacking, so it is of great significance to explore the stacking type and twist angle of few layer BP. However, the effects of accurately characterizing the layer number, stacking type and twist angle of BP on its electronic and optical properties have not been fully resolved. ..Ultra-low frequency Raman spectroscopy can reveal key information of stacking black phosphorus, which is a very important experimental method. ..Based on the above analysis, this project aims at studying the effects of layer numbers, stacking types and twist angles of BP on its photoelectric properties. Utilizing ultra-low-frequency Raman spectroscopy and angular resolved Raman spectroscopy, the collective compression mode (CCM) and breathing mode (BM) will be characterize. The dependence between the three parameters, including layer numbers, stacking types and twist angles, and the frequency and intensity of CCM and BM will be analysed, which will not only realise the rapid identification but also reveal the effects of stacking type and twist angle on the photoelectric characteristics of layer coupling, band structures and optical properties of BP. By establishing a prediction model based on ultra-low frequency vibration modes, it is possible to tune the electronic band gaps of various stacking BP and to optimise the standard linear-chain model. This project provides a novel experimental idea for revealing the stacking mechanism and photoelectric characteristics of multilayer BP, and provides scientific evidence for its application in the field of photoelectricity.

黑磷作为一种高迁移率、能隙可调的各向异性直接带隙新型二维材料，弥补了石墨烯和过渡金属硫化物的缺点，应用前景广阔。多层二维材料的光电特性与其堆垛类型有关，因此探索黑磷烯的堆垛方式与旋转角度意义重大。然而，实验上精准表征层数、堆垛方式、旋转角度及其对黑磷烯光电特性的影响的研究尚不充分。超低频拉曼光谱能揭示黑磷堆垛的关键信息，是十分重要的实验方法。鉴于此，本项目拟以研究黑磷烯堆垛层数、方式和旋转角度对其光电特性的影响为目标，利用超低频与角分辨拉曼光谱，表征集体压缩模和呼吸模，研究黑磷烯层数、堆垛方式和角度与振动模频率、强度的依赖关系，实现快速精准指认，并分析其对层间耦合、能带结构和光学特性的影响。通过建立基于超低频振动模的预测模型，达到对各类堆垛黑磷烯的电子带隙调谐，并对线性原子链模型优化补充。本项目为揭示多层黑磷烯的堆垛机制和光电特性提供了新的实验思路，为实现其在光电领域的应用提供了科学依据。

黑磷作为一种高迁移率、能隙可调的各向异性直接带隙新型二维材料，弥补了石墨烯和过渡金属硫化物的缺点，应用前景广阔。多层二维材料的光电特性与其堆垛类型有关，因此探索黑磷烯的堆垛方式与旋转角度意义重大。然而，实验上精准表征层数、堆垛方式、旋转角度及其对黑磷烯光电特性的影响的研究尚不充分。超低频拉曼光谱能揭示黑磷堆垛的关键信息，是十分重要的实验方法。. 因此，本项目以研究多层黑磷烯堆垛层数、方式和扭曲角度对其光电特性的影响为目标，提出了利用超低频拉曼结合角分辨拉曼光谱表征黑磷烯超低频剪切模和呼吸模的方法，实现了对黑磷烯层数的快速精确指认以及对黑磷烯堆垛方式和扭曲角度的表征，并结合已有理论得到不同堆垛层数、方式、角度对黑磷烯电子结构和光学特性的影响，建立了基于超低频特征峰振动频率与强度的预测模型，达到对不同堆叠方式与角度的多层黑磷烯的电子带隙调谐，进而对线性原子链模型进行优化补充。超低频拉曼峰的偏振研究表明，大多数双层黑磷样品倾向于AB堆垛。此外，我们能够通过超低频Ag3和B3g模式的最小强度来指认双层黑磷样本的各种堆叠扭曲角。. 通过本项目的研究，为多层黑磷烯堆垛层数、堆垛方式和旋转角度的表征提供重要的实验方法，也为其他各向异性二维材料的拉曼光谱研究提供可借鉴的实验思路。这是实现新型二维材料黑磷烯在晶体管、光电器件、生物医药、太阳能电池等领域的应用急需解决的关键问题，具有重要的研究意义和应用价值。