Michail Antonios, Yang Jerry A, Filintoglou Kyriakos, Balakeras Nikolaos, Nattoo Crystal Alicia, Bailey Connor Scott, Daus Alwin, Parthenios John, Pop Eric, Papagelis Konstantinos
Department of Physics, University of Patras, Patras 26504, Greece.
Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH - ICE/HT), Patras 26504, Greece.
ACS Appl Mater Interfaces. 2024 Sep 18;16(37):49602-49611. doi: 10.1021/acsami.4c07216. Epub 2024 Sep 3.
Monolayer transition metal dichalcogenides are intensely explored as active materials in 2D material-based devices due to their potential to overcome device size limitations, sub-nanometric thickness, and robust mechanical properties. Considering their large band gap sensitivity to mechanical strain, single-layered TMDs are well-suited for strain-engineered devices. While the impact of various types of mechanical strain on the properties of a variety of TMDs has been studied in the past, TMD-based devices have rarely been studied under mechanical deformations, with uniaxial strain being the most common one. Biaxial strain on the other hand, which is an important mode of deformation, remains scarcely studied as far as 2D material devices are concerned. Here, we study the strain transfer efficiency in MoS- and WSe-based flexible transistor structures under biaxial deformation. Utilizing Raman spectroscopy, we identify that strains as high as 0.55% can be efficiently and homogeneously transferred from the substrate to the material in the transistor channel. In particular, for the WSe transistors, we capture the strain dependence of the higher-order Raman modes and show that they are up to five times more sensitive compared to the first-order ones. Our work demonstrates Raman spectroscopy as a nondestructive probe for strain detection in 2D material-based flexible electronics and deepens our understanding of the strain transfer effects on 2D TMD devices.
单层过渡金属二硫属化物因其有望克服器件尺寸限制、亚纳米级厚度和强大的机械性能，而被作为二维材料基器件中的活性材料进行深入研究。考虑到它们的大带隙对机械应变的敏感性，单层过渡金属二硫属化物非常适合用于应变工程器件。虽然过去已经研究了各种类型的机械应变对多种过渡金属二硫属化物性能的影响，但基于过渡金属二硫属化物的器件在机械变形下却很少被研究，其中单轴应变是最常见的一种。另一方面，就二维材料器件而言，双轴应变作为一种重要的变形模式，仍然几乎没有得到研究。在这里，我们研究了基于二硫化钼和硒化钨的柔性晶体管结构在双轴变形下的应变传递效率。利用拉曼光谱，我们确定高达0.55%的应变可以有效地、均匀地从衬底传递到晶体管沟道中的材料上。特别是对于硒化钨晶体管，我们捕捉到了高阶拉曼模式的应变依赖性，并表明它们的灵敏度比一阶模式高出五倍。我们的工作证明了拉曼光谱作为二维材料基柔性电子器件应变检测的无损探针，并加深了我们对二维过渡金属二硫属化物器件应变传递效应的理解。
