EFRI 2-DARE: 2D Crystals formed by Activated Atomic Layer Deposition

非技术：过渡金属硫化物(TMC)结晶为二维原子片，具有不同寻常的电子性质，可以通过改变层的数量、排列和组成来改变。这些参数的调整提供了必须克服的制造挑战，以实现在电子、光子学和相关技术中的潜在应用。该项目将研究新的薄膜和超导器件的沉积和加工方法。这项研究将使原子级薄膜能够在与低成本玻璃和塑料基板兼容的低温下形成。还将研究将金属接触层和介电薄膜与TMC集成到延长工作设备中的技术。该项目将支持五名研究生的研究，并为来自宾夕法尼亚州代表性不足群体和经济困难地区的本科生和高中生提供暑期研究机会。本科生还将参加该项目，作为他们通过宾夕法尼亚大学学习工厂组织的高级Capstone工程设计项目的一部分。技术：这个EFRI 2-DARE项目旨在为单层和多层过渡金属硫化物(TMC)开发新的合成路线和集成策略，从而能够发现基本的结构-性质关系，探索新的物理现象，并创造新的薄膜和超导器件技术。将开发一种用于WSe2、FeSe、NbSe2和相关2D材料的激活原子层沉积(ALD)工艺，该工艺结合了热源和等离子体源以促进前体分解，从而降低了在van der Waals表面沉积和介电/金属集成所需的衬底温度。外延模板和衬底图案化将被用来控制成核和促进面内力，以诱导2D岛在大范围内的自组装。现场诊断将被用来提供对ALD化学的洞察。超高分辨率像差校正(扫描)透射电子显微镜(S)成像和相关光谱技术将使单层和多层膜中的缺陷能够直接成像和化学表征，从而提供常规透射电子显微镜无法始终获取的信息。将开发器件制造工艺，以便能够详细研究TMC中的电子传输和超导电性。门控电流-电压测量、霍尔效应和准静态电容-电压测量将用于表征WSe2和WS2薄膜器件的输运特性。还将研究栅极FeSe和NbSe结构中的超导电性，以寻求高温和非常规超导电性。

Non-Technical: Transition metal chalcogenides (TMCs) crystallize as two-dimensional sheets of atoms, giving them unusual electronic properties that can be varied by changing the number, arrangement and compositions of the layers. The adjustment of these parameters provides manufacturing challenges that must be overcome to realize potential applications in electronics, photonics and related technologies. The project will research new deposition and processing methods for novel thin film and superconducting devices. This research will enable atomic level film formation at low temperatures that are compatible with low-cost glass and plastic substrates. Techniques to integrate metal contact layers and dielectric films with TMCs to produe working devices will also be researched. The project will support the research of five graduate students and summer research opportunities for undergraduates and high school students from underrepresented groups and economically challenged regions of Pennsylvania. Undergraduates will also participate in the project as part of their senior capstone engineering design project organized through the Learning Factory at Penn State.Technical: This EFRI 2-DARE project is aimed at the development of new synthetic routes and integration strategies for monolayer and multilayer transition metal chalcogenides (TMCs) to enable discovery of fundamental structure-property relationships, the exploration of novel physical phenomena, and the creation of new thin film and superconducting device technologies. An activated atomic layer deposition (ALD) process for WSe2, FeSe, NbSe2 and related 2D materials will be developed that incorporates thermal and plasma sources to promote precursor decomposition, thereby enabling reduced substrate temperatures that are needed for deposition and dielectric/metal integration on van der Waals surfaces. Epitaxial templating and substrate patterning will be used to control nucleation and promote in-plane forces to induce self-assembly of 2D islands over large areas. In-situ diagnostics will be used to provide insights into the ALD chemistry. Ultra-high resolution aberration-corrected (scanning) transmission electron microscopy ((S)TEM) imaging and related spectroscopy techniques will enable direct imaging and chemical characterization of defects in monolayer and multilayer films, providing information not always accessible by conventional TEM. Device fabrication processes will be developed to enable detailed studies of electrical transport and superconductivity in TMCs. Gated current-voltage measurements, Hall-effect, and quasi-static capacitance-voltage measurements will be used to characterize the transport properties of WSe2 and WS2 thin film devices. Superconductivity in gated FeSe and NbSe2 structures will also be examined to seek high-temperature and unconventional superconductivity.