Silicon Telluride, A 2D Material with Unique Variable Structure

碲化硅，一种具有独特可变结构的二维材料

• 批准号: 1709528
• 负责人: Xiao Shen
• 金额: $ 39.27万
• 依托单位: University of Memphis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709528&HistoricalAwards=false
• 关键词: Silicon; Telluride; 2D; Material; Unique

Non-Technical Description: Two-dimensional (2D) sheet-like materials composed of one or a few layers of atoms often display properties dramatically different from the same materials in bulk form. This project focuses on a new two-dimensional material, namely silicon telluride, which has unique variable structures where Si atoms form Si-Si pairs to fill the sites between surrounding Te atoms. Each Si pair has four possible orientations, with easily achievable rotations between each other. The flexibility in Si dimer orientations enables unique structural variability and opens opportunities for new phenomena, properties, and functionalities. The research team combines theoretical and experimental studies to develop 2D materials with desirable properties and to achieve a fundamental understanding of the unique phenomenon in silicon telluride, which is expected to make significant impacts on the field of low-dimensional materials and electronic and optoelectronic industry. The research activities are integrated with educational efforts, augmenting the undergraduate and graduate curriculums through hands-on projects, enriched course materials, and summer workshops on nanomaterials to inspire the students' interest in science. Additional project activities including outreach to high school students and teachers through summer research activities and demonstrations at local high schools further extend the impact of this project on the community.Technical Description: Atomically thin, two-dimensional materials such as graphene, dichalcogenides, and black phosphorus offer unique properties and have attracted significant attention by the scientific community. Silicon telluride is a new 2D material, recently demonstrated with a thickness of a few atomic layers. It has a unique crystal structure in which the Te atoms form a hexagonal close-packed structure, and Si atoms form Si-Si dimers to fill the two-thirds of the interstitial sites between the Te atoms, with each Si dimer taking one of the four possible orientations: three in-plane and one out-plane. The Si dimers can easily rotate their orientations due to the small energy barriers and thus can enable dynamic structural variations, such as flipped Si dimers and domain boundaries between regions of different Si dimer orientations, which are expected to interact with charge carriers and excitons to give rise to new electronic and optical phenomena and properties. In this project, the team combines theoretical investigations based on first-principles calculations and experimental deposition and characterization approaches to develop a fundamental understanding of how structural variations in 2D silicon telluride affect the material properties by exploring various strain and doping optimization strategies.

非技术描述：由一层或几层原子组成的二维（2D）片状材料通常显示出与块状形式的相同材料显著不同的性质。该项目的重点是一种新的二维材料，即碲化硅，它具有独特的可变结构，其中Si原子形成Si-Si对以填充周围Te原子之间的位置。每个Si对具有四种可能的取向，彼此之间容易实现旋转。Si二聚体取向的灵活性使独特的结构可变性成为可能，并为新的现象、性质和功能开辟了机会。该研究团队将理论和实验研究相结合，开发具有理想性能的2D材料，并对碲化硅中的独特现象进行基本了解，预计将对低维材料和电子及光电行业产生重大影响。研究活动与教育工作相结合，通过动手项目，丰富的课程材料和纳米材料暑期研讨会来增强本科生和研究生的兴趣，以激发学生对科学的兴趣。通过夏季研究活动和在当地高中的演示，项目还将进一步扩大对社区的影响。技术说明：石墨烯、二硫属化合物和黑磷等原子级薄的二维材料具有独特的性质，吸引了科学界的极大关注。碲化硅是一种新型2D材料，最近证明其厚度只有几个原子层。它具有独特的晶体结构，其中Te原子形成六方密堆积结构，并且Si原子形成Si-Si二聚体以填充Te原子之间的三分之二的间隙位置，每个Si二聚体采取四种可能的取向之一：三个面内和一个面外。Si二聚体可以容易地旋转它们的取向，这是由于小的能量势垒，因此可以实现动态结构变化，例如翻转的Si二聚体和不同Si二聚体取向的区域之间的畴边界，预期其与电荷载流子和激子相互作用以产生新的电子和光学现象和性质。在这个项目中，该团队结合了基于第一原理计算的理论研究和实验沉积和表征方法，通过探索各种应变和掺杂优化策略，对2D碲化硅的结构变化如何影响材料特性进行了基本了解。

项目成果

Pressure-Induced Insulator–Metal Transition in Silicon Telluride from First-Principles Calculations

• DOI: 10.1021/acs.jpcc.1c00636
• 发表时间: 2021-01
• 期刊: Journal of Physical Chemistry C
• 影响因子: 3.7
• 作者: R. Bhattarai;X. Shen

Ultra-high mechanical flexibility of 2D silicon telluride

• DOI: 10.1063/1.5120533
• 发表时间: 2020-01-13
• 期刊: APPLIED PHYSICS LETTERS
• 影响因子: 4
• 作者: Bhattarai, Romakanta;Shen, Xiao
• 通讯作者: Shen, Xiao

Predicting a Novel Phase of 2D SiTe2

• DOI: 10.1021/acsomega.0c02048
• 发表时间: 2020-07-14
• 期刊: ACS OMEGA
• 影响因子: 4.1
• 作者: Bhattarai, Romakanta;Shen, Xiao
• 通讯作者: Shen, Xiao

Morphology control of Si2Te3 nanostructures synthesized by CVD

• DOI: 10.1007/s10854-018-9158-1
• 发表时间: 2018-04
• 期刊: Journal of Materials Science: Materials in Electronics
• 作者: Keyue Wu;J. Cui

Anisotropic Optical Properties of 2D Silicon Telluride

• DOI: 10.1557/adv.2020.186
• 发表时间: 2020-01-01
• 期刊: MRS ADVANCES
• 影响因子: 0.8
• 作者: Bhattarai, Romakanta;Chen, Jiyang;Shen, Xiao
• 通讯作者: Shen, Xiao