摘要
在这个工作，我们学习夹层声子颤动模式， layer-numberdependent 原子地薄的金来 diselenide 的光 bandgap，和各向异性的光致发光(PL ) 系列(ReSe <sub>2</sub>) 第一次。在 ReSe <sub>2</sub> 的 ultralow 频率夹层拉曼系列和解决极化的高频率拉曼系列允许它的层数字和水晶取向的鉴定。而且， PL 大小显示出材料的各向异性的光排放紧张，它的 bandgap 在单层在体积从 1.26 eV 增加到 1.32 eV。拉曼模式和 PL 系列的层数字依赖的学习揭示相对弱的货车 der Waals 相互作用并且二维(2D ) 在原子地薄的 ReSe <sub>2</sub> 的量监禁。在单层和多层的 ReSe <sub>2</sub> 的吸引人的各向异性的夹层相互作用和悦耳的光转变的试验性的观察在在在红外线附近的光谱工作的各向异性的 optoelectronic 设备的发展为这材料的进一步的探索建立基础，它为在光通讯并且红外线的察觉到的许多应用是重要的。
In this work, we study the interlayer phonon vibration modes, the layer-number- dependent optical bandgap, and the anisotropic photoluminescence （PL） spectra of atomically thin rhenium diselenide （ReSe2） for the first time. The ultralow frequency interlayer Raman spectra and the polarization-resolved high frequency Raman spectra in ReSe2 allow the identification of its layer number and crystal orientation. Furthermore, PL measurements show the anisotropic optical emission intensity of the material with its bandgap increasing from 1.26 eV in the bulk to 1.32 eV in the monolayer. The study of the layer-number dependence of the Raman modes and the PL spectra reveals relatively weak van der Waal＇s interaction and two-dimensional （2D） quantum confinement in the atomically thin ReSe2. The experimental observation of the intriguing anisotropic interlayer interaction and tunable optical transition in monolayer and multilayer ReSe2 establishes the foundation for further exploration of this material in the development of anisotropic optoelectronic devices functioning in the near-infrared spectrum, which is important for many applications in optical communication and infrared sensing,
基金
Acknowledgements This work is partially supported by National Science Foundation EFRI 2-DARE program （No. 1542815） and Zumberge Research and Innovation Fund Award. P.-H. Tan acknowledges support from the National Natural Science Foundation of China （Nos. 11225421, 11474277, and 11434010）.
