转角双层石墨烯纳米片单、双光子吸收特性研究

One and Two⁃Photon Absorption Properties of Twist Bilayer Graphene Nanosheets

杨志远 邹怡 王金刚

Zhiyuan YANG Yi ZOU Jingang WANG

辽宁石油化工大学 理学院，辽宁 抚顺 113001

College of Science，Liaoning Petrochemical University，Fushun Liaoning 113001，China

基于第一性原理和波函数分析理论，研究了锯齿形边界的不同旋转角度（转角）的双层转角石墨烯纳米片（Z?TwBLG?NS）的单光子吸收光谱（One?photon absorption,OPA）和双光子吸收光谱（Two?photon absorption,TPA）以及它们的电子激发特性。研究了OPA和TPA随转角变化的规律及特性；对电子跃迁特性进行了可视化分析。结果表明，当转角不为0°时，吸收峰出现了不同程度的红移，说明转角对体系的吸收光谱有调制作用；转角不为0°的双层转角石墨烯纳米片具有明显的边界效应，电子和空穴等值面主要分布在边缘处。揭示了莫尔纹对电荷转移的限制作用，体现在聚集于莫尔纹处的电子和空穴分布的差异。研究结果为转角调控下的双层石墨烯纳米片光学特性提供了物理机制的分析依据，也为相关的研究工作提供了思路和方法。

Based on the first principles and wave function analysis theory,the one?photon absorption (OPA) spectra and two?photon absorption (TPA) spectra of the zigzag boundaries Twisted Bilayer Graphene Nanosheets (Z?TwBLG?NS) with different twist angles and their electronic excitation characteristics were studied.Firstly,the law and properties of the change of one?photon absorption spectrum and two?photon absorption spectrum with different twist angle were studied.Secondly,the characteristics of electron transition were analyzed visually.The results show that the absorption peaks are red?shifted to different degrees when the angle is not 0°,indicating that the angle modulates the absorption spectra of the system.The Z?TwBLG?NS with an angle of no 0° had obvious boundary effect, and the isosurface of electrons and holes were mainly distributed at the edge. Finally,the limiting effect of moiré pattern on electron transfer was revealed,which was reflected in the difference in the density of electrons and holes gathered in the moiré pattern.This study provides the analytical basis of physical mechanism for the generation of optical properties of Z?TwBLG?NS under the control of twist angle,as well as a research methodology for related research work.

辽宁省自然科学基金面上项目(2022?MS?363);辽宁省教育厅基本科研项目(LJKMZ20220735);2023年度辽宁省教育厅高校基本科研项目(JYTMS20231431)

10.12422/j.issn.1006-396X.2023.06.008