DMREF: GOALI: Tetrahedral Ferroelectrics

非技术描述：铁电性是通过施加外部电场来逆转自发电极化的能力。这一特性对许多现代电子和光学技术至关重要，但尽管经过数十年的努力，将铁电材料与基于传统半导体的电子设备直接集成的成功有限。部分挑战是，传统的铁电材料表现出与硅等商业半导体非常不同的晶体结构、成键和缺陷密度。这个项目试图通过引入一种新的铁电材料来解决这个问题，这种材料具有商业半导体常见的四面体成键结构。将一种新功能引入四面体半导体将代表着集成电子和光学设备能力的一步变化。这个项目将发现和开发新的四面体铁电材料，并导致对铁电的新的机理理解。该项目将通过对学生和博士后的教育来强调劳动力发展，这些学生和博士后经过培训，通过综合计算和实验的现代方法加速材料发现。通过与工业合作伙伴Broadcom，Inc.的密切合作，将加速技术进步。技术描述：四面体铁电材料，如改性氮化铝(AlN)，提供了一个独特的机会，扩大我们对极化重定向的基本理解，并发现具有启用非线性介电性能的新材料系列。最近发现的四面体铁电材料突显了对铁电性和极性半导体的科学理解上的空白。目前的项目解决了三组基本问题：(1)可切换极化与胁迫场、顺电转变和/或硬度有何关系？(2)四面体铁电材料中的开关机制(S)是什么？(3)局域结构、单个和聚集的点缺陷以及合成对开关和击穿有何影响？这些问题将通过综合计算和实验来解决，扩大对铁电和极性半导体的基本原理的理解。在四面体半导体中实现铁电性代表着半导体器件能力的潜在阶段性变化，并为对抗复杂氧化物中的缺陷调节提供了一种有吸引力的替代方案。这个项目将扩展铁电和半导体物理学，通过更好地理解极化重定向的机制，欢迎一系列迄今未知的基于四面体的系统进入已知铁电宇宙，同时向四面体半导体工具箱引入新的内在能力。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。

Nontechnical Description:Ferroelectricity is the ability to reverse a spontaneous electrical polarization by the application of an external electric field. This property is crucial to many modern electronic and optical technologies, but there has been limited success directly integrating ferroelectric materials with electronics based on conventional semiconductors despite decades of efforts. Part of the challenge is that traditional ferroelectrics exhibit very different crystal structures, bonding, and defect densities from commercial semiconductors such as silicon. This project seeks to resolve this problem by introducing a new class of ferroelectric materials with a tetrahedral bonding structure common to commercial semiconductors. Introducing a new function to tetrahedral semiconductors will represent a step change in the capabilities of integrated electronic and optical devices. This project will discover and develop new tetrahedral ferroelectrics and result in a new mechanistic understanding of ferroelectricity. The project will emphasize workforce development, through the education of students and post-docs trained to accelerate materials discovery via modern approaches to integrated computation and experiment. Technological advances will be accelerated through close collaboration with an industrial partner, Broadcom, Inc. Technical Description:Tetrahedral ferroelectrics such as modified aluminum nitride (AlN) offer a unique opportunity to extend our fundamental understanding of polarization reorientation and to discover new families of materials with enabling non-linear dielectric properties. The recent discovery of tetrahedral ferroelectrics has highlighted gaps in the scientific understanding of ferroelectricity and of polar semiconductors. The current project addresses three sets of fundamental questions: (1) How is switchable polarization related to coercive field, a paraelectric transition and/or stiffness? How is coercive field related to structure? (2) What is (are) the switching mechanism(s) in tetrahedral ferroelectrics? (3) How do local structure, individual and clustered point defects, and synthesis affect switching and breakdown? These questions will be addressed via integrated computation and experimentation, expanding the understanding of the fundamentals of ferroelectricity and of polar semiconductors alike. Enabling ferroelectricity in tetrahedral semiconductors represents a potential step change in semiconductor device capability and offers an attractive alternative to fighting defect accommodation in complex oxides. This project will expand ferroelectric and semiconductor physics, through a greater understanding of the mechanisms of polarization reorientation that welcomes a family of heretofore unknown tetrahedra-based systems to the universe of known ferroelectrics while simultaneously introducing a new intrinsic capability to the toolbox of tetrahedral semiconductors.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.