EAPSI: Experimental Study of an Atomically-Thin, Semiconducting/Metallic Material to Develop Next-Generation Nanotechnology

最近在实现原子薄电子学方面的爆炸性进展是由于对将超越传统硅基半导体技术的物理限制的新的制造方法、材料和器件操作原理的搜索。研究表明，过渡金属二卤化物(TMD)在电子转移到原始半导体材料中时会发生结构转变，从而产生金属状态。这提供了一条通向原子锐化金属-半导体结的途径，并可能实现一种新的高效、全2D集成电路技术。本项目将使用扫描隧道显微镜(STM)研究原子薄TMD中的结构变化机制及其操纵。这种仪器的特点是有一个原子尖端，可以直接将电子转移到材料中，并以原子尺度的精度提供结构和电子信息。还将研究作为温度函数的稳定性，以便了解设备的合适工作温度。这项研究的结果将加深我们对这些材料用于纳米器件制造的控制的理解。这项工作将与澳大利亚墨尔本莫纳什大学二维材料实验物理研究的领军人物迈克尔·富勒教授合作完成。该项目旨在利用扫描隧道显微镜(STM)和扫描隧道光谱(STS)将金属-半导体界面的原子结构与局部电子性质联系起来。STM和STS将在相边界附近的低温下进行，以提供局部电子态密度的地形表征。然后，可以研究可控地向原始材料或相界中注入电子的效果，同时注意相界的迁移、相的产生和电子态的变化。相边界迁移也将作为温度的函数进行研究。该奖项由东亚和太平洋夏季学院项目资助一名美国研究生的暑期研究，由NSF和澳大利亚科学院联合资助。

The recent explosion in progress towards realizing atomically thin electronics has resulted from the search for newer fabrication methods, materials, and device operation principles that will advance beyond the physical limits of conventional silicon-based semiconductor technology. Transition metal dichalcogenides (TMDs) have been shown to undergo a structural transformation to produce a metallic state upon transfer of electrons into the pristine semiconducting material. This gives a route towards atomically sharp metal-semiconductor junctions and could enable a new class of efficient, fully 2D integrated circuit technologies. This project will study the structural change mechanism, and manipulation thereof, in atomically thin TMDs using a scanning tunneling microscope (STM). This instrument features an atomically sharp tip that can directly transfer electrons into the material as well as provide structural and electronic information with atomic-scale precision. Stability as a function of temperature will also be studied in order to inform about suitable operating temperatures for devices. The results of this research will deepen our understanding of control over these materials for nano-device fabrication. This work will be done in collaboration with Professor Michael Fuhrer, a leader in experimental physics research of two-dimensional materials, at Monash University in Melbourne, Australia. This project aims to correlate atomic structures with local electronic properties at the metallic-semiconducting interface using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). STM and STS will be done at low temperature in the vicinity of a phase boundary to provide topographical characterization of the local electronic density of states. Then, the effect of controllably injecting electrons into the pristine material or into a phase boundary, with attention being paid to phase boundary migration, phase creation, and changes in electronic state can be studied. Phase boundary migration will also be studied as a function of temperature. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.