Collaborative Research: Tailoring Terahertz Emission in Ultrafast Multi-Functional Devices using Reduced-Dimensional Hybrid Metal Perovskites

非技术性：太赫兹技术为未来的计算和通信带来了巨大的希望。使用轻质、低成本和坚固的材料的节能和小型化的THz源是长期追求的目标。然而，很少有材料具有实现工作装置所需的属性。具有降低的维度的金属卤化物钙钛矿是一类新的半导体，具有很大的应用前景。它们可以便宜地合成和溶液处理，具有吸引人的电子特性，并容忍缺陷。这些特性引起了人们对太阳能电池和柔性显示器应用的极大兴趣。钙钛矿也显示出作为高性能THz源的前景。值得注意的是，这些特性可以通过自旋电子学（自旋电子学）来控制，自旋电子学利用了设备中电子的基本特性。这使得钙钛矿与磁性材料的界面成为可能，从而实现自旋电子THz发射器。该项目将导致低成本和高能效的THz设备，具有互补的磁，光和电子功能。PI将通过将研究与教育相结合来教育研究生和本科生，包括那些来自代表性不足群体的学生。已建立和发展的推广计划将用于涉及K-12学生与该项目。技术：该项目的重点是实现一个自旋电子控制的宽带太赫兹发射的RD-HMH/铁磁体异质结构。该研究包括三个研究重点：（1）利用低成本旋涂方法制备的降维混合金属卤化物（RD-HMH）多晶薄膜，利用RD-HMH中重金属元素的快速自旋弛豫（类似于开关）和有效的自旋-电荷相互转换，展示概念验证的自旋电子混合THz发射器。一个彻底的，基本的物理理解的超快产生的太赫兹辐射的RD-HMH/铁磁体异质结构将被解开。(2)通过工程RD-HMH单晶定制THz发射。晶片级单晶基太赫兹发射器将被设计和优化，具有可调带宽和高质量（Q-）因子，以补充多晶薄膜发射器。(3)通过使用器件构建块的多功能化学合成路线优化THz发射。具有可调量子阱效应的高质量合成RD-HMH候选物的可用池已经准备好被制造成高效的THz发射器，允许THz产生的自旋电子学和磁性控制，其可以潜在地用于利用THz的逻辑应用。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评估被认为值得支持。影响审查标准。

Nontechnical: Terahertz technologies hold great promise for future computing and communications. Energy-efficient and miniaturized THz sources using light-weight, low-cost, and robust materials are a long sought goal. Few materials, however, possess the attributes needed to realize working devices. Metal halide perovskites with reduced dimensionality are a new class of semiconductors with great promise for such applications. They can be inexpensively synthesized and solution processed, have attractive electronic properties, and tolerate defects. These properties have led to great interest for applications in solar cells and flexible displays. Perovskites also show promise as high performance THz sources. Remarkably, these properties can be controlled via spin electronics (spintronics) that exploit the fundamental properties of electrons in devices. This makes it possible to interface perovskites with magnetic materials, enabling spintronic THz emitters. This project will lead to low-cost and energy-efficient THz devices with complementary magnetic, optical and electronic functions. The PIs will educate graduate and undergraduate students, including those from underrepresented groups, by integrating research with education. Established and developing outreach programs will be used to involve K-12 students with the project.Technical:This project focuses on the realization of a spintronic control of the broadband THz emission in RD-HMH/Ferromagnet heterostructures. The research consists of three research thrusts: (1) Demonstrate the proof-of-concept spintronic hybrid THz emitter using reduced dimensional-hybrid metal halide (RD-HMH) polycrystalline thin films prepared by a low-cost spin-coating approach, taking advantage of the fast relaxation of spin (akin to a switch) and efficient spin-to-charge interconversion thanks to the heavy metal elements in RD-HMHs. A thorough, fundamental physical understanding of the ultrafast generation of THz emission in RD-HMH/Ferromagnet heterostructures will be unraveled. (2) Tailor the THz emission via engineering RD-HMH single crystals. Wafer-scale single crystals-based THz emitters will be designed and optimized with tunable bandwidth as well as high quality (Q-) factors, in complement to that of polycrystalline-film emitters. (3) Optimize the THz emission via versatile chemical synthetic routes using device building blocks. The available pool of high-quality synthesized RD-HMH candidates with tunable quantum-well effects are ready to be fabricated into efficient THz emitters, allowing the spintronic and magnetic control of THz generation that can be potentially used for logic applications utilizing THz-wave emission and absorption.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.