Kim Dong Hyeon, Lee Chanwoo, Kim Sung Hyuk, Jeong Byeong Geun, Yun Seok Joon, Suh Hyeong Chan, Lee Dongki, Kim Ki Kang, Jeong Mun Seok
Department of Physics, Hanyang University, Seoul 04763, Korea.
Department of Energy Science, Sungkyunkwan University, Suwon 16419, Korea.
Nanophotonics. 2024 Jan 19;13(7):1069-1077. doi: 10.1515/nanoph-2023-0826. eCollection 2024 Mar.
Transition metal dichalcogenide (TMDs) heterostructure, particularly the lateral heterostructure of two different TMDs, is gaining attention as ultrathin photonic devices based on the charge transfer (CT) excitons generated at the junction. However, the characteristics of the interface of the lateral heterostructure, determining the electronic band structure and alignment at the heterojunction region, have rarely been studied due to the limited spatial resolution of nondestructive analysis systems. In this study, we investigated the confined phonons resulting from the phonon-disorder scattering process involving multiple disorders at the lateral heterostructure interface of MoS-WS to prove the consequences of disorder-mediated deformation in the band structure. Moreover, we directly observed variations in the metal composition of the multi-disordered nanoscale alloy Mo W S, consisting of atomic vacancies, crystal edges, and distinct nanocrystallites. Our findings through tip-enhanced Raman spectroscopy (TERS) imply that a tens of nanometer area of continuous TMDs alloy forms the multi-disordered interface of the lateral heterostructure. The results of this study could present the way for the evaluation of the TMDs lateral heterostructure for excitonic applications.
过渡金属二硫属化物（TMDs）异质结构，特别是两种不同TMDs的横向异质结构，作为基于结处产生的电荷转移（CT）激子的超薄光子器件正受到关注。然而，由于无损分析系统的空间分辨率有限，很少有人研究决定异质结区域电子能带结构和排列的横向异质结构界面的特性。在本研究中，我们研究了在MoS-WS横向异质结构界面处由涉及多种无序的声子-无序散射过程产生的受限声子，以证明能带结构中无序介导变形的后果。此外，我们直接观察了由原子空位、晶体边缘和不同纳米微晶组成的多无序纳米级合金Mo W S的金属成分变化。我们通过针尖增强拉曼光谱（TERS）得到的结果表明，几十纳米面积的连续TMDs合金形成了横向异质结构的多无序界面。本研究结果可为评估用于激子应用的TMDs横向异质结构提供方法。
