Hybrid Graphene-Ferroelectric Devices

该项目由材料研究部（DMR）的电子和光子材料（EPM）项目以及电气、通信和网络系统部（ECCS）的电子、光子和磁器件（EPMD）项目联合资助。技术：该研究项目研究混合石墨烯-铁电材料和器件。混合材料提供了结合独特的二维狄拉克费米电子结构的强度和石墨烯中的高载流子迁移率以及铁电材料中的高功能性的希望。该研究的目的是克服不良的极化屏蔽通过使用人工分层的超晶格材料在外延薄膜的形式，其中的相变温度和材料的介电响应可以精确定制的铁电材料的表面上的吸收。本文的研究主要集中在两个方面：（1）.铁电材料被用于将与其接触的石墨烯片电荷掺杂到比常规的半导体材料高得多的程度。基于铁电电荷掺杂的原理，原子力显微镜用于纳米结和电路的“按需”制造，允许定义具有任意设计的尖锐电位分布，从而通过扫描探针成像和电输运测量来探索狄拉克电子散射的物理学。（二）、铁电材料用于在特定方向上对石墨烯片施加精确控制的应变，以改变电子特性并研究理论预测的规范场效应。非技术性：该项目涉及物理学、材料科学和器件工程相结合的跨学科领域的基础和应用研究问题，具有高度的技术相关性。石墨烯的独特性质被利用在利用铁电场效应和压电应变的新器件结构中。该项目中研究的原型器件可以形成下一代电子产品的种子，例如具有低功耗和高迁移率的新型晶体管，非易失性存储器件以及基于应变石墨烯的器件。研究生，以及本科生和高中生，在跨学科的环境中接受培训，学习薄膜沉积，光刻，原子力显微镜和电气特性。

This project is jointly funded by the Electronic and Photonic Materials (EPM) Program in the Division of Materials Research (DMR) and the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems (ECCS).Technical: This research project studies hybrid graphene-ferroelectric materials and devices. The hybrid materials offer promise for combining the strength of the unique two-dimensional Dirac Fermionic electronic structure and high carrier mobility in graphene plus the high functionality in ferroelectric materials. The research is designed to overcome undesirable polarization screening by absorbates on the surface of ferroelectric materials by the use of artificially layered superlattice materials in the form of epitaxial thin films, in which the phase transition temperature and dielectric response of the material can be precisely tailored. The research focuses mainly on two aspects: (1). A ferroelectric material is used to charge dope a graphene sheet in contact with it to a much higher extent than the conventional dielectrics can. Based on the principle of ferroelectric charge doping, atomic force microscopy are used for "on-demand" fabrication of nano-junctions and circuits, allowing definition of sharp potential profiles with arbitrary designs, enabling exploration of the physics of Dirac electron scattering through both scanning probe imaging and electrical transport measurements. (2). A ferroelectric material is used to exert precisely controlled strain on a graphene sheet in particular directions to modify the electronic properties and to study the theoretically predicted gauge field effects.Non-technical: The project addresses basic and applied research issues in an interdisciplinary area that combines physics, materials science and device engineering, with high technological relevance. The unique properties of graphene are exploited in new device structures that utilize both the ferroelectric field effect and piezoelectric strain. Prototype devices studied in the project could form the seed for next-generation electronics such as novel transistors with low-power consumption and high mobility, non-volatile memory devices, and devices based on strained graphene. Graduate students, as well as undergraduate and high-school students, are trained in an interdisciplinary environment and learn thin-film deposition, lithography, atomic force microscopy, and electrical characterization.