High Endurance Phase-Change Devices for Electrically Reconfigurable Optical Systems

用于电可重构光学系统的高耐久性相变器件

基本信息

批准号：
2028624
负责人：
Nathan Youngblood
金额：
$ 38万
依托单位：
University of Pittsburgh
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2028624&HistoricalAwards=false
关键词：
Endurance Phase Change Devices Electrically

项目摘要

Award Title:High-endurance phase-change devices for electrically reconfigurable optical systemsNon-Technical Abstract:Materials whose optical properties can be tuned electrically are essential to operations of many modern technologies that we rely on daily, for example, smartphone displays and fiber internet. For emerging applications in tunable optical components, high-speed computing, and advanced optical storage, a group of materials that can be reconfigured at the atomic level, known as “phase-change materials,” is particularly promising. When their atoms are arranged in either an ordered or disordered state, these materials exhibit a dramatic, stable, and reversible change in their optical properties, which could enable devices with very compact form-factor, low energy consumption and insensitivity to vibration. While many proof-of-concept optical devices have been demonstrated using phase-change materials, few can be controlled using electrical signals—a prerequisite for real world implementation. Additionally, these electrically controlled phase-change devices have shown poor endurance and switching cyclability, the cause of which is not well understood. The team proposes to address this challenge by first investigating the role of heat and mechanical expansion in the various layers comprising these devices using time-dependent optical and electrical measurements. Secondly, the team will use high resolution imaging techniques to study the role that migration of various types of atoms has on the reversibility of the phase-change material. Finally, the team will use these results to construct phase-change devices with improved reliability and explore the possibility of scaling them up to sizes needed for applications requiring larger tunable optical components. The team seeks to educate middle-/high-school students on topics related to novel materials in daily life from school districts with historically serving under-represented minorities, using a combination of interactive workshops and hands-on demos. This project also provides training for two graduate students in advanced device fabrication and characterization techniques, and hosts undergraduates from underrepresented groups during the summer months to broaden participation in STEM-related fields.Technical Abstract:Phase-change materials, such as Ge2Sb2Te5 and GeTe, are particularly promising for reconfigurable optical devices owing to their fast, dramatic, non-volatile, and reversible change in refractive index. Experimental demonstrations of reconfigurable smart windows, reflective displays, metasurfaces, and photonic devices for memory and computing have re-ignited interests in these materials. For phase-change devices with dimensions greater than the optical wavelength, an electro-thermal approach to switching is most promising, but limited prior work showed poor endurance and cyclability (1000 cycles or less) compared to the high endurances (greater than 10 million cycles) demonstrated for phase-change data storage. The team proposes that the endurance is limited by poorly matched thermal properties of materials within these devices, while the degrading optical contrast often observed is due to phase segregation and void formation in the phase-change layer. To validate this hypothesis, the project has three aims: (1) improve the lifetime of electro-thermal phase-change devices by properly matching the thermal expansion coefficients of the materials within the device layers; (2) reduce the cycling-induced degradation of optical contrast by reducing thermal gradients within the device and improving deposition conditions; and (3) identify the effects and limitations of scaling on phase-change optical devices. The proposed approach will overcome the limited cyclability of these electro-thermally switched phase-change devices by studying the thermal response of the device layers through complementary thermal-mechanical modelling, dynamic optoelectronic measurements, and advanced nano-characterization techniques. The insights gained by understanding and addressing the current limitations of electro-thermally controlled optical phase-change films are expected to be broadly applicable to such fields as tunable optical coatings, non-von Neumann computing, electrical-optical conversion, and reconfigurable photonic and RF systems.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.

奖项名称：用于电可重构光学系统的高耐久性相变器件非技术摘要：光学特性可以电调节的材料对于我们日常依赖的许多现代技术的运行至关重要，例如智能手机显示器和光纤互联网。对于可调谐光学元件、高速计算和先进光存储等新兴应用，一组可以在原子水平上重新配置的材料（称为“相变材料”）特别有前途。这些材料以有序或无序的状态排列，其光学特性表现出显着、稳定和可逆的变化，这可以使设备具有非常紧凑的外形、低能耗和对振动不敏感。概念光学器件已经使用相变材料进行了演示，但很少可以使用电信号进行控制——这是现实世界实现的先决条件。此外，这些电控相变器件的耐用性和开关循环性较差，其原因并非如此。很好理解。该团队建议通过首先使用与时间相关的光学和电气测量来研究热和机械膨胀在这些设备的各个层中的作用来应对这一挑战，其次，该团队将使用高分辨率成像技术来研究迁移的作用。最后，该团队将利用这些结果来构建可靠性更高的相变器件，并探索将其放大到需要更大可调谐光学元件的应用所需尺寸的可能性。该团队致力于教育中/高中学生。结合互动研讨会和实践演示，围绕来自历史上为弱势群体服务的学区的日常生活中的新颖材料相关的主题，该项目还为两名研究生提供先进设备制造和表征技术的培训。暑期期间，来自代表性不足群体的本科生主持，以扩大对 STEM 相关领域的参与。技术摘要：相变材料，如 Ge2Sb2Te5 和 GeTe，由于其快速、可重构智能窗口、反射式显示器、超表面以及用于存储和计算的光子器件的实验演示重新点燃了人们对这些材料尺寸大于的相变器件的兴趣。光波长，电热开关方法是最有前途的，但有限的先前工作表明，与高耐久性（大于 1000 万次）相比，耐久性和可循环性（1000 次或更少）较差该团队提出，耐久性受到这些设备内材料不匹配的热性能的限制，而经常观察到的光学对比度下降是由于相变层中的相分离和空隙形成造成的。为了验证这一假设，该项目有三个目标：（1）通过适当匹配器件层内材料的热膨胀系数来提高电热相变器件的寿命；（2）减少循环引起的退化；通过减少设备内的热梯度来实现光学对比度改善沉积条件；（3）确定缩放对相变光学器件的影响和限制，所提出的方法将通过研究器件层的热响应来克服这些电热切换相变器件的有限循环性。互补的热机械建模、动态光电测量和先进的纳米表征技术通过理解和解决电热控制光学相变薄膜的当前局限性而获得的见解预计将广泛适用于可调谐光学涂层等领域。 ,非冯诺依曼计算、电光转换以及可重构光子和射频系统。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

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Electronically Reconfigurable Photonic Switches Incorporating Plasmonic Structures and Phase Change Materials

结合等离子体结构和相变材料的电子可重构光子开关

DOI：
10.1002/advs.202200383
发表时间：
2022-01
期刊：
Advanced Science
影响因子：
15.1
作者：
Farmakidis, Nikolaos;Youngblood, Nathan;Lee, June Sang;Feldmann, Johannes;Lodi, Alessandro;Li, Xuan;Aggarwal, Samarth;Zhou, Wen;Bogani, Lapo;Pernice, Wolfram HP;et al
通讯作者：
et al

Nonvolatile band switching using transparent phase-change materials on Bragg structures

在布拉格结构上使用透明相变材料进行非易失性能带切换

DOI：
10.1117/12.2647868
发表时间：
2023-03
期刊：
and Technologies XXVII
影响因子：
0
作者：
Nobile, Nicholas A.;Lian, Chuanyu;Sun, Hongyi;Mills, Brian;Popescu, Cosmin Constantin;Hu, Juejun;Ríos, Carlos;Youngblood, Nathan
通讯作者：
Youngblood, Nathan

AnalogVNN: A fully modular framework for modeling and optimizing photonic neural networks

AnalogVNN：用于建模和优化光子神经网络的完全模块化框架

DOI：
10.1063/5.0134156
发表时间：
2022-10-14
期刊：
ArXiv
影响因子：
0
作者：
Vivswan Shah;N. Youngblood
通讯作者：
N. Youngblood

Photonic (computational) memories: tunable nanophotonics for data storage and computing

光子（计算）存储器：用于数据存储和计算的可调谐纳米光子学

DOI：
10.1515/nanoph-2022-0089
发表时间：
2022-05
期刊：
Nanophotonics
影响因子：
7.5
作者：
Lian, Chuanyu;Vagionas, Christos;Alexoudi, Theonitsa;Pleros, Nikos;Youngblood, Nathan;Ríos, Carlos
通讯作者：
Ríos, Carlos

Coherent Photonic Crossbar Arrays for Large-Scale Matrix-Matrix Multiplication

用于大规模矩阵-矩阵乘法的相干光子交叉阵列