Nanowires from Layered van der Waals Crystals: Opportunities for Tuning Structure and Function in 1D-2D Hybrid Nanostructures

层状范德华晶体纳米线：调整 1D-2D 混合纳米结构结构和功能的机会

• 批准号: 1904843
• 负责人: Peter Sutter
• 金额: $ 52万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904843&HistoricalAwards=false
• 关键词: Nanowires; Layered; van; der; Waals

Part 1: Non-Technical SummarySemiconductor nanowires are of technological interest as a class of functional components for electronics, light emission, energy conversion, or quantum computation, which can be mass-produced with exceptionally high crystal quality by simple growth processes. To date, research has almost exclusively focused on nanowires of traditional semiconductor materials, such as silicon or germanium, in which the atoms are tightly bonded to their neighbors in a three-dimensional crystal. This project, which is supported by the Solid State and Materials Chemistry program at NSF, explores opportunities in tuning structure and properties that arise in nanowires of layered semiconductors, in which atoms are tightly bonded in atomically thin sheets that are in turn held together by much weaker forces. Coordinated efforts in studying the synthesis of such layered nanowires and in exploring their distinct electronic and optoelectronic properties aim to uncover relationships between crystal structure, electronic structure and the flow of electrical current, as well as light absorption and emission, which are import for technological applications. In addition to the targeted technical advances, the project provides far-reaching educational and training opportunities for the involved graduate and undergraduate students. It includes dedicated outreach to high-school students from rural areas that gives student-teacher teams the opportunity to participate in hands-on activities related to the research. Under the guidance of the researchers the students prepare new science learning materials, which they bring back to their school to share their experience with their peers and to help build excitement for careers in STEM disciplines.Part 2: Technical SummaryExtensive research on planar 2D and layered chalcogenide semiconductors has been driven by outstanding electronic, optoelectronic, mechanical and chemical properties of these materials. In contrast, little attention has been paid to the possibility of combining the concepts of vapor-liquid-solid (VLS) nanowire growth and van der Waals (vdW) epitaxy to realize layered chalcogenide nanowires. The few existing studies have treated those systems on an equal footing with conventional 3D-crystalline nanowires without addressing the opportunities for materials design that arise in vdW crystals. This project, which is supported by the Solid State and Materials Chemistry program at NSF, explores the unique crystallographic degrees of freedom of vdW nanowires and their control via tailored VLS growth processes. Examples of distinct properties include layering along different directions, facile materials integration due to lifted lattice matching requirements, and a tendency toward spontaneous interlayer twist that adds up to an overall chirality and whose magnitude is controlled by the wire diameter. Coordinated growth and characterization of selected materials with focus on anisotropic metal monochalcogenide semiconductors provide insight into the atomistic growth mechanisms of vdW nanowires and heterostructures. Structure and morphology are correlated to single-nanowire charge transport, and to optoelectronic properties probed by cathodoluminescence spectroscopy at resolution below the exciton radius to address the role of layer stacking and twist, confinement, excitonic effects, as well as interfacial carrier transfers in heterostructures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第一部分：非技术概述半导体纳米线作为一类用于电子学、光发射、能量转换或量子计算的功能组件具有技术意义，其可以通过简单的生长工艺以极高的晶体质量大规模生产。迄今为止，研究几乎完全集中在传统半导体材料的纳米线上，如硅或锗，其中原子在三维晶体中与相邻原子紧密结合。该项目由NSF的固态和材料化学项目支持，探索了调整层状半导体纳米线中出现的结构和性质的机会，其中原子紧密结合在原子薄片中，这些薄片反过来又通过弱得多的力结合在一起。在研究这种层状纳米线的合成以及探索其独特的电子和光电特性方面的协调努力旨在揭示晶体结构，电子结构和电流流动之间的关系，以及光吸收和发射，这对于技术应用是重要的。除了有针对性的技术进步，该项目还为参与的研究生和本科生提供了意义深远的教育和培训机会。它包括专门针对农村地区高中学生的外联活动，使学生-教师团队有机会参加与研究有关的实践活动。在研究人员的指导下，学生们准备了新的科学学习材料，并将其带回学校，与同学们分享他们的经验，并帮助建立对STEM学科职业生涯的兴奋。第2部分：技术总结平面2D和层状硫族化物半导体的广泛研究受到这些材料出色的电子，光电，机械和化学性能的推动。相比之下，很少有人注意到将气-液-固（VLS）纳米线生长和货车德瓦尔斯（vdW）外延的概念相结合以实现层状硫族化物纳米线的可能性。现有的少数研究已经将这些系统与传统的3D晶体纳米线平等对待，而没有解决vdW晶体中出现的材料设计机会。该项目由NSF的固态和材料化学项目支持，探索了vdW纳米线的独特晶体学自由度及其通过定制的VLS生长过程的控制。不同性质的实例包括沿沿着不同方向分层、由于晶格匹配要求提高而容易的材料整合、以及自发夹层扭曲的趋势，自发夹层扭曲加起来形成整体手性并且其大小由线直径控制。选定材料的协调生长和表征，重点关注各向异性金属单硫属化物半导体，提供了对vdW纳米线和异质结构原子生长机制的深入了解。结构和形态与单纳米线电荷传输相关，并且与通过阴极发光光谱法以低于激子半径的分辨率探测的光电性质相关，以解决层堆叠和扭曲、限制、激子效应的作用，该奖项反映了NSF的法定使命，并通过使用基金会的知识产权进行评估，被认为值得支持。优点和更广泛的影响审查标准。

项目成果

Tunable Layer Orientation and Morphology in Vapor–Liquid–Solid Growth of One-Dimensional GeS van der Waals Nanostructures

• DOI: 10.1021/acs.chemmater.1c00289
• 发表时间: 2021-06
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: E. Sutter;Jacob S. French;P. Sutter

Van der Waals heterostructures

• DOI: 10.1038/s43586-022-00139-1
• 发表时间: 2022-07-28
• 期刊: NATURE REVIEWS METHODS PRIMERS
• 作者: Castellanos-Gomez, Andres;Duan, Xiangfeng;Sutter, Peter
• 通讯作者: Sutter, Peter

Frontiers in hybrid and interfacial materials chemistry research

• DOI: 10.1557/mrs.2020.271
• 发表时间: 2020-11-01
• 期刊: MRS BULLETIN
• 影响因子: 5
• 作者: Guiton, Beth S.;Stefik, Morgan;Talham, Daniel R.
• 通讯作者: Talham, Daniel R.

Van der Waals Nanowires with Continuously Variable Interlayer Twist and Twist Homojunctions

• DOI: 10.1002/adfm.202006412
• 发表时间: 2020-12
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: P. Sutter;J. Idrobo;E. Sutter