论文标题
使用近场宽带吸收显微镜在WXMO1-XS2合金中可视化带移动和层间耦合
Visualization of Band Shifting and Interlayer Coupling in WxMo1-xS2 Alloys using Near-Field Broadband Absorption Microscopy
论文作者
论文摘要
超出限制限制的光学吸收光谱法提供了有关组合物和堆叠的二维材料的分级带结构的深刻信息，其中直接/间接带隙，层间耦合，滑动，可能的缺陷以及可能的缺陷会显着修改其光电功能，例如光电效应效率。在这里，我们首次使用近场宽带吸收显微镜首次可视化单层和双层过渡金属二甲基合金的空间变化带结构。近场和空间图表现出源自组成扩散和层间耦合的相互作用引起的激子带。这些结果使我们能够将双层合金的顶层识别为纯WS2。我们还使用无像差的近场透射图像来划定合金和纯过渡金属二分法的确切边界。这项技术可以在堆叠科学时代的各种分层结构方面提供新的见解，以寻求新型的量子光电设备。
Beyond-diffraction-limit optical absorption spectroscopy provides profound information on the graded band structures of composition-spread and stacked two-dimensional materials, in which direct/indirect bandgap, interlayer coupling, sliding, and possible defects significantly modify their optoelectronic functionalities such as photoluminescence efficiency. We here visualize the spatially-varying band structure of monolayer and bilayer transition metal dichalcogenide alloys for the first time by using near-field broadband absorption microscopy. The near-field-spectral and -spatial diagrams manifest the excitonic band shift that results from the interplay of composition spreading and interlayer coupling. These results enable us to identify the top layer of the bilayer alloy as pure WS2. We also use the aberration-free near-field transmittance images to demarcate the exact boundaries of alloyed and pure transition metal dichalcogenides. This technology can offer new insights on various layered structures in the era of stacking science in quest of novel quantum optoelectronic devices.
