EAPSI: Synthesis and Electrical Transport Properties of Chemical Vapor Deposited Two-Dimensional Semiconductor Layers of Tungsten Diselenide

努力改善和提高硅技术是纳米技术和材料科学领域目前面临的挑战。在这方面，对可以生产厚度等于几个原子层的新型材料的研究，例如过渡金属二硫属化物，可能会为几种电子和光电应用带来突破性的解决方案。 这些先进纳米材料的合成和电输运特性可以导致电子产品中各种数字和模拟电路的潜在改进，例如广播接收器和无线通信。在这个项目中，将制备二维二硒化钨（WSe 2）原子层，并在结构和电学上进行表征。这项研究将在中国科学技术大学国家同步辐射实验室的李松教授的指导下进行，提供了一个与最先进的实验室设施（如微电子器件纳米制造的洁净室）的著名专家合作的机会。2D纳米材料由于其电子性质、表面均匀性以及以各种不同方式进行功能化和掺杂的能力而变得特别感兴趣。特别是，原子薄WSe 2是已知的表现出相对较高的载流子迁移率和直接带隙，不像石墨烯？s零带隙。可以通过微调生长参数来研究合成WSe 2层的化学气相沉积方法。使用一系列的方法，包括高分辨率透射电子显微镜和拉曼光谱，WSe 2薄膜的物理和形态特征。然后，各种电和光输运性质，如场效应载流子的迁移率和光电性能，这些器件将被调查。该项目将分析分层和电输运性质之间关系的确切性质，并对单层WSe 2作为金属氧化物半导体场效应晶体管在电子纳米器件应用中的集成提供新的见解。该NSF EAPSI奖支持美国研究生的研究，并与中国科技部合作资助。

Efforts to improve and enhance silicon technology is a present challenge in the field of nanotechnology and materials science. In that respect, the investigation of novel materials that can be produced with thickness equal to a few atomic layers, for example transition metal dichalgoenides, might lead to breakthrough solutions for several electronic and optoelectronic applications. The synthesis and electrical transport properties of these advanced nanomaterials can lead to potential improvements in a wide variety of digital and analog circuits in electronics, such as broadcast receivers and wireless communications. In this project, two dimensional atomic layers of tungsten diselenide (WSe2) will be prepared and characterized structurally and electrically. This research will be carried out under the mentorship of Professor Li Song at the National Synchrotron Radiation Laboratory at the University of Science and Technology of China, offering an opportunity to work with a noted expert in state-of-the-art laboratory facilities such as a cleanroom for microelectronic device nanofabrication. 2D nanomaterials have become of particular interest given their electronic properties, surface homogeneity, and their ability to be functionalized and doped in a variety of different ways. In particular, atomically thin WSe2 is known to exhibit a relatively high charge carrier mobility and a direct band gap, unlike graphene?s zero band gap. The chemical vapor deposition method to synthesize layers of WSe2 can be investigated by fine-tuning the growth parameters. Using an array of methods, including high-resolution transmission electron microscopy and Raman spectroscopy, the WSe2 thin films can be physically and morphologically characterized. Then, various electrical and optical transport properties, such as the field effect mobility of charge carriers and photoelectronic properties, of these devices will be investigated. This project will analyze the exact nature of the relation between layering and electrical transport properties and enable new insight into the integration of monolayered WSe2 as metal-oxide-semiconductor field effect transistors in electronic nanodevice applications. This NSF EAPSI award supports the research of a U.S. graduate student and is funded in collaboration with the Chinese Ministry of Science and Technology.