Surface Acoustic Wave Spectroscopy Offers Novel, Broadband, and Spatially-Resolved Insight into Transition Metal Dichalcogenides Films

表面声波光谱为过渡金属二硫化物薄膜提供了新颖、宽带和空间分辨的见解

• 批准号: 388433893
• 负责人: Professor Dr. Hubert Johannes Krenner
• 金额: --
• 依托单位: Department of Chemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/388433893?language=en
• 关键词: Surface; Acoustic; Wave; Spectroscopy; Offers

This bi-national German-US project is focused on studying the electrical transport properties of two-dimensional (2D) transition metal dichalcogenides by applying surface acoustic wave spectroscopy. This method is contactless and provides insight into the transport properties modulations in absence of any perturbation caused by electrical contacts crucially needed for alternative methods. The approach utilizes surface acoustic waves generated and recorded by means of interdigital transducers that are spaced millimeters away from the films under investigation. The films studied in this project are grown using a fully scalable approach, chemical vapor deposition, on technologically mature and emerging functional substrates for hybrid device architectures. Optical excitation is used to modify the transport properties of the films at diffraction-limited spatial resolution rivaling that of current photoluminescence and Raman maps. This allows new insight into the spatial variation of transport properties in transition metal dichalcogenide films. The German-US research team explores the impact of composition gradients in alloys of transition metal dichalcogenides, grain boundaries, lateral interfaces, and other material perturbations on the local conductivity. It aims to unravel the fundamental electrical transport properties of these in the technologically extremely important radio frequency domain (100 MHz up to 3 GHz) of next-generation advanced transition metal dichalcogenide heterostructures, from single flakes to substrate-scale continuous films. Emphasis will be set on the practical application of large-area films. These will be applied as the active detection medium of a surface acoustic wave-interrogated camera. A composition-graded film advances this device towards a spectrometer. Both devices are fully compatible with existing surface acoustic wave technology and can be interfaced and addressed via RF-ID tagged wireless communication. The project combines the expertise on acousto-optic and acousto-electric spectroscopy and control of optically active nanosystems using surface acoustic waves at Universität Augsburg and preparative techniques available at the University of California, Riverside. The research is expected to enhance the understanding of carrier transport in transition metal dichalcogenide films with defects, heterojunctions or other local variations. The acquired knowledge is a foundation for design of novel devices that incorporate heterojunctions of such films as functional elements.

这个德国-美国两国项目的重点是通过应用表面声波光谱研究二维（2D）过渡金属二硫属化物的电输运性质。该方法是非接触式的，并且在没有由替代方法所迫切需要的电接触引起的任何扰动的情况下提供了对输运性质调制的洞察。该方法利用表面声波产生和记录的叉指换能器，间隔毫米远离调查中的电影。在这个项目中研究的薄膜生长使用一个完全可扩展的方法，化学气相沉积，在技术成熟和新兴的功能基板的混合设备架构。光激发是用来修改在衍射限制的空间分辨率媲美当前的光致发光和拉曼地图的膜的传输特性。这使得新的洞察过渡金属二硫属化物薄膜中的传输特性的空间变化。德美研究小组探索了过渡金属二硫属化物合金中的成分梯度、晶界、横向界面和其他材料扰动对局部电导率的影响。它的目的是解开这些在技术上非常重要的射频域（100 MHz至3 GHz）的下一代先进的过渡金属二硫属化物异质结构的基本电输运特性，从单片到基板规模的连续薄膜。重点将放在大面积薄膜的实际应用上。这些将被应用作为表面声波询问相机的主动检测介质。一种成分渐变的薄膜将这种装置推向光谱仪。这两种设备都与现有的表面声波技术完全兼容，并且可以通过RF-ID标记的无线通信进行接口和寻址。该项目结合了声光和声电光谱学的专业知识，并在奥格斯堡大学使用表面声波控制光学活性纳米系统，并在加州大学滨江提供制备技术。该研究有望增强对过渡金属二硫属化物薄膜中载流子输运的理解，包括缺陷、异质结或其他局部变化。所获得的知识是一个新的设备，将异质结的功能元件，这样的电影设计的基础。