npj 2D Materials and Applications ( IF 9.7 ) Pub Date : 2020-07-10 , DOI: 10.1038/s41699-020-0155-x Georgy A. Ermolaev , Yury V. Stebunov , Andrey A. Vyshnevyy , Dmitry E. Tatarkin , Dmitry I. Yakubovsky , Sergey M. Novikov , Denis G. Baranov , Timur Shegai , Alexey Y. Nikitin , Aleksey V. Arsenin , Valentyn S. Volkov
Layered semiconductors such as transition metal dichalcogenides (TMDs) offer endless possibilities for designing modern photonic and optoelectronic components. However, their optical engineering is still a challenging task owing to multiple obstacles, including the absence of a rapid, contactless, and the reliable method to obtain their dielectric function as well as to evaluate in situ the changes in optical constants and exciton binding energies. Here, we present an advanced approach based on ellipsometry measurements for retrieval of dielectric functions and the excitonic properties of both monolayer and bulk TMDs. Using this method, we conduct a detailed study of monolayer MoS2 and its bulk crystal in the broad spectral range (290–3300 nm). In the near- and mid-infrared ranges, both configurations appear to have no optical absorption and possess an extremely high dielectric permittivity making them favorable for lossless subwavelength photonics. In addition, the proposed approach opens a possibility to observe a previously unreported peak in the dielectric function of monolayer MoS2 induced by the use of perylene-3,4,9,10-tetracarboxylic acid tetrapotassium salt (PTAS) seeding promoters for MoS2 synthesis and thus enables its applications in chemical and biological sensing. Therefore, this technique as a whole offers a state-of-the-art metrological tool for next-generation TMD-based devices.
中文翻译:
单层和块状MoS 2的宽带光学特性
诸如过渡金属二硫化氢(TMD)之类的层状半导体为设计现代光子和光电组件提供了无限可能。但是,由于存在多种障碍,包括缺乏快速,无接触以及获得其介电功能以及可靠地评估光学常数和激子结合能变化的可靠方法,它们的光学工程仍然是一项艰巨的任务。在这里,我们提出了一种基于椭圆偏振测量的先进方法,用于检索单层和整体TMD的介电函数和激子特性。使用这种方法,我们进行了单层MoS 2的详细研究它的块状晶体在宽光谱范围内(290-3300 nm)。在近红外和中红外范围内,这两种配置似乎都没有光吸收,并且具有极高的介电常数,这使其非常适合无损亚波长光子学。另外,所提出的方法为观察到通过使用per3,4,9,10-四羧酸四钾盐(PTAS)种子促进剂为MoS 2诱导的单层MoS 2介电功能中以前未报道的峰提供了可能性。合成,因此使其能够应用于化学和生物传感。因此,该技术总体上为下一代基于TMD的设备提供了最新的计量工具。