Placing spins in semiconductors

将自旋放入半导体中

• 批准号: 2102306
• 负责人: Hemamala Karunadasa
• 金额: $ 43.51万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102306&HistoricalAwards=false
• 关键词: Placing; spins; semiconductors

Non-technical summaryThe remarkable optical and electronic properties of metal-halide semiconductors, which adopt the perovskite crystal structure, make them excellent candidates as component materials in solar cells and light emitting devices (e.g., LEDs). Perovskites that excel in these applications, however, are nonmagnetic. Thus, metal-halides with excellent optical and electronic properties and a high density of magnetic spins remain essentially unknown. With this project, supported by the Solid State and Materials Chemistry and Electronic and Photonic Materials programs in the Division of Materials Research, Professor Hema Karunadasa and her research group at Stanford University propose the design and synthesis of new magnetic semiconductors that form in solution. These materials, composed primarily of metal ions and halides, are expected to display new phenomena stemming from interactions between a) the spins of magnetic ions and b) the spins and conducting electrons. The new materials designed in this project could have strong applications in the field of spintronics, where magnetic spins add an additional degree of control over electronic devices, has great potential in next-generation high-speed and low-power information technologies. Revealing such properties in materials that can be deposited from solution as films could dramatically cut costs of such applications. Further, new phenomena of fundamental scientific interest may be realized in these materials, including a) magnetic spins that cannot order, even at very low temperatures, leading to exotic spin patterns, b) spins that align to create permanent magnets, and c) magnetic spins that control the flow of electrons inside a material. Local high-school students will participate in the research through summer programs and the PI will continue redesigning general chemistry to introduce undergraduate students to materials chemistry earlier in the curriculum. Through a collaboration with Hampton University, Virginia, materials developed in this project will be assessed for near- and mid-IR emission. Undergraduates at Hampton University and Stanford University will learn how to control light through the incorporation of magnetic impurities in metal-halides. Technical summaryThe remarkable optoelectronic properties of halide perovskites have rendered them excellent candidates for photovoltaic and phosphor applications. The common perovskites explored for these applications, however, are nonmagnetic. Thus, metal-halides that possess comparable optoelectronic properties and contain a high density of spins remain essentially unknown. Spintronics has great potential in next-generation high-speed and low-power information technologies, for example, magnetoresistance has applications in high-density data storage. Revealing such phenomena in materials that can be deposited from solution as films could dramatically cut costs of such applications. This project, supported by the Solid State and Materials Chemistry and Electronic and Photonic Materials programs in the Division of Materials Research, is addressing this challenge by developing new synthetic routes toward the self-assembly of magnetic semiconductors in solution. These new materials are anticipated to display unprecedented phenomena in metal-halides, derived from spin-spin and spin-carrier interactions. Specific objectives of the proposed work are: 1) the design of new metal-halide architectures that contain spins in the organic or inorganic components, 2) the development of magnetic metal-halides with dispersive electronic bands and tunable carrier concentrations, 3) the characterization of magnetic, charge transport, and optoelectronic properties of these new materials. Fundamentally new phenomena in metal-halides will also be targeted, including magnetic frustration, spin polarization, and coupling between itinerant electrons and an embedded magnetic sublattice. High-school students will participate in summer research programs and the PI will continue to redesign freshman chemistry to introduce students to materials chemistry earlier in the curriculum. Through collaboration with Hampton University, Virginia, materials developed in this project will be assessed for mid- and near-IR emission. Undergraduates at Hampton University and Stanford University will study how to develop lanthanide-containing metal-halides for applications in photonics.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.

非技术摘要采用钙钛矿晶体结构的金属卤化物半导体具有卓越的光学和电子特性，使其成为太阳能电池和发光器件（例如 LED）组件材料的绝佳候选材料。然而，在这些应用中表现出色的钙钛矿是非磁性的。因此，具有优异光学和电子特性以及高磁自旋密度的金属卤化物基本上仍然未知。 在材料研究部的固态和材料化学以及电子和光子材料项目的支持下，斯坦福大学的 Hema Karunadasa 教授和她的研究小组提出了在溶液中形成的新型磁性半导体的设计和合成方案。这些材料主要由金属离子和卤化物组成，预计将显示出源自 a) 磁性离子自旋和 b) 自旋和导电电子之间相互作用的新现象。 该项目设计的新材料可以在自旋电子学领域有强大的应用，其中磁自旋增加了对电子设备的额外控制程度，在下一代高速和低功耗信息技术中具有巨大潜力。揭示可以从溶液中沉积为薄膜的材料的这些特性可以极大地降低此类应用的成本。此外，在这些材料中可能会实现具有基础科学意义的新现象，包括a）即使在非常低的温度下也无法有序的磁自旋，从而导致奇异的自旋模式，b）对齐以产生永磁体的自旋，以及c）控制材料内电子流动的磁自旋。当地高中生将通过暑期项目参与研究，PI 将继续重新设计普通化学，以便在课程的早期向本科生介绍材料化学。通过与弗吉尼亚州汉普顿大学的合作，该项目开发的材料将进行近红外和中红外发射评估。汉普顿大学和斯坦福大学的本科生将学习如何通过在金属卤化物中掺入磁性杂质来控制光。技术摘要卤化物钙钛矿卓越的光电特性使其成为光伏和荧光粉应用的绝佳候选者。然而，为这些应用探索的常见钙钛矿是非磁性的。因此，具有相当的光电特性并包含高自旋密度的金属卤化物基本上仍然未知。自旋电子学在下一代高速、低功耗信息技术方面具有巨大潜力，例如磁阻在高密度数据存储方面有应用。揭示可以从溶液中沉积为薄膜的材料中的这种现象可以大大降低此类应用的成本。该项目得到了材料研究部的固态和材料化学以及电子和光子材料项目的支持，正在通过开发新的合成路线来解决这一挑战，以实现磁性半导体在溶液中的自组装。这些新材料预计将在金属卤化物中表现出前所未有的现象，这些现象源自自旋-自旋和自旋-载流子相互作用。拟议工作的具体目标是：1）设计在有机或无机成分中包含自旋的新型金属卤化物结构，2）开发具有色散电子带和可调载流子浓度的磁性金属卤化物，3）表征这些新材料的磁性、电荷传输和光电特性。金属卤化物中的根本性新现象也将成为目标，包括磁挫败、自旋极化以及流动电子与嵌入式磁性亚晶格之间的耦合。高中生将参加夏季研究项目，PI 将继续重新设计新生化学，以便在课程的早期向学生介绍材料化学。通过与弗吉尼亚州汉普顿大学的合作，该项目开发的材料将进行中红外和近红外发射评估。汉普顿大学和斯坦福大学的本科生将研究如何开发用于光子学应用的含镧系金属卤化物。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值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

Mosaic Cu I −Cu II −In III 2D Perovskites: Pressure‐Dependence of the Intervalence Charge Transfer and a Mechanochemical Alloying Method

马赛克 Cu I –Cu II –In III 二维钙钛矿：压力 – 层间电荷转移的依赖性和机械化学合金化方法

• DOI: 10.1002/anie.202300957
• 发表时间: 2023
• 期刊: Angewandte Chemie International Edition
• 作者: Li, Jiayi;Matheu, Roc;Ke, Feng;Liu, Zhenxian;Lin, Yu;Karunadasa, Hemamala I.
• 通讯作者: Karunadasa, Hemamala I.