Collaborative Research: Revealing the Role of Structural Modulations on the Electronic Properties of Hexagonal Chalcogenide Perovskite Semiconductors

合作研究：揭示结构调制对六方硫族化物钙钛矿半导体电子性能的作用

• 批准号: 2122070
• 负责人: Rohan Mishra
• 金额: $ 32万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2122070&HistoricalAwards=false
• 关键词: Collaborative; Research; Revealing; Role; Structural

NON-TECHNICAL DESCRIPTION: Chalcogenides that contain sulfur, selenium, and tellurium are functional semiconductors with broad applications in information storage and processing, and in energy conversion. A subset of these materials with hexagonal symmetry demonstrate strong light-matter interactions with potential applications in sensing and communication. This project employs an integrated theoretical and experimental approach to establish axioms elucidating the role of subtle changes in composition and structure in these materials on electronic properties, and to achieve desired properties such as optical anisotropy by controlling composition and structure. Graduate students are being trained to use a mix of theory and experiments to address fundamental problems in materials science and engineering. Education activities focus on preparing graduate and undergraduate students for a workforce needed to realize advanced energy and information technologies. TECHNICAL DETAILS: The project seeks to unravel the role of non-stoichiometry and structural modulations on the electronic structure of hexagonal chalcogenides perovskites, and control their physical properties including optical anisotropy and electronic transitions, by changing their composition and structure. The research employs vapor-transport single crystal growth and pulsed laser deposition to grow chalcogenide perovskites. A combination of x-ray, neutron, and electron-based probes are used to characterize structure and composition at multiple length scales. Physical properties are characterized using optical spectroscopy and electrical transport studies. First-principles electronic structure calculations are used to establish atomic origins of the experimentally observed properties. Education aspects include training of graduate and undergraduate students to use an integrated theoretical and experimental approach to investigate and design materials. This project supports the development of course modules on atomic-scale modeling and atom-by-atom growth of functional materials, and the organization of symposia at national meetings on functional semiconductors and chalcogenide perovskites.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.

非技术描述：含硫、硒和碲的硫族化合物是一种功能半导体，在信息存储和处理以及能量转换方面有着广泛的应用。这些材料中具有六角对称性的一部分展示了强烈的光-物质相互作用，在传感和通信方面具有潜在的应用。该项目采用理论和实验相结合的方法来建立公理，阐明这些材料中组成和结构的细微变化对电子性质的作用，并通过控制组成和结构来实现所需的性质，如光学各向异性。研究生正在接受培训，利用理论和实验相结合的方法来解决材料科学和工程中的基本问题。教育活动的重点是为研究生和本科生培养实现先进能源和信息技术所需的劳动力。技术细节：该项目旨在揭示非化学计量比和结构调制对六方硫属钙钛矿电子结构的作用，并通过改变其组成和结构来控制其物理性质，包括光学各向异性和电子跃迁。本研究采用气相传输单晶生长和脉冲激光沉积的方法生长硫系钙钛矿。X射线、中子和基于电子的探针的组合被用来在多个长度尺度上表征结构和成分。用光学光谱学和电学输运研究来表征其物理性质。第一性原理电子结构计算被用来确定实验观察到的性质的原子起源。教育方面包括培训研究生和本科生使用综合的理论和实验方法来调查和设计材料。该项目支持开发关于功能材料的原子尺度建模和逐个原子生长的课程模块，以及在关于功能半导体和硫系钙钛矿的国家会议上组织研讨会。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Modeling temperature, frequency, and strain effects on the linear electro-optic coefficients of ferroelectric oxides

• DOI: 10.1063/5.0090072
• 发表时间: 2021-06
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: Yang Liu;Guodong Ren;Tengfei Cao;Rohan Mishra;J. Ravichandran

Epitaxial Thin Films of a Chalcogenide Perovskite

• DOI: 10.1021/acs.chemmater.1c02202
• 发表时间: 2021-05
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Mythili Surendran;Huandong Chen;Boyang Zhao;A. Thind;Shantanu Singh;T. Orvis;Huan Zhao;Jae-Kyung Han