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。这种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，直接将铁电材料与基于传统半导体的电子集成的成功有限。部分挑战在于传统铁电体表现出与商业半导体（如硅）非常不同的晶体结构，键合和缺陷密度。该项目试图通过引入一类新的铁电材料来解决这个问题，该铁电材料具有商用半导体常见的四面体键合结构。将新功能引入四面体半导体将代表集成电子和光学器件能力的一步变化。该项目将发现和开发新的四面体铁电体，并导致对铁电性的新的机理理解。该项目将强调劳动力发展，通过对学生和博士后的教育，通过现代综合计算和实验方法来加速材料发现。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：四面体铁电体（如改性氮化铝（AlN））提供了一个独特的机会，可以扩展我们对极化重取向的基本理解，并发现具有非线性介电特性的新材料系列。最近发现的四面体铁电体突出了铁电性和极性半导体的科学理解的差距。目前的项目解决了三组基本问题：（1）可切换的极化如何与矫顽场，顺电过渡和/或刚度？矫顽场与结构有什么关系？(2)四面体铁电体的开关机制是什么？(3)局部结构、单个和聚集的点缺陷以及合成如何影响开关和击穿？这些问题将通过综合计算和实验来解决，扩大对铁电性和极性半导体基本原理的理解。在四面体半导体中实现铁电性代表了半导体器件能力的潜在阶跃变化，并提供了对抗复杂氧化物中缺陷容纳的有吸引力的替代方案。该项目将扩展铁电和半导体物理，通过更好地理解极化重定向的机制，欢迎一个迄今未知的四面体家族，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准。

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.