Collaborative Research: Combinatorial solution processing of optical phase change materials

相变材料（PCMs）是一类在微观结构转变后光学性质发生剧烈变化的化合物。这种独特的特性允许创建新颖的基于pcm的可重构或可编程光学系统。与传统光学的特性是固定的不同，这种可编程光学的功能可以动态配置，以适应不断变化的应用需求。该项目由材料研究部陶瓷项目支持，开创了加速发现PCM合金的变革性合成范例，专门为光学应用量身定制。与传统昂贵的真空系统制备pcm不同，该项目探索了基于解决方案的打印——类似于照片的彩色打印——作为可扩展的pcm合成路线。研究人员还开发了新的方法来实现高通量筛选和下选pcm，以实现针对特定光学应用的材料性能优化。从这项研究中获得的基本见解对节能数据通信、有源超材料、光子存储、反射显示、模拟光学计算等应用具有广泛的影响。此外，该项目还为中佛罗里达大学和麻省理工学院的本科生提供了研究机会。此外，研究人员还开发了一门专门针对玻璃材料的大规模开放在线课程（MOOC），从而填补了玻璃科学教育方面的关键空白。技术综述相变材料（PCMs）是一类微观结构发生转变后光学性质发生剧烈变化的化合物。然而，由于传统PCM合成的低通量和无法在操作中可靠地测量其性质，新型光学PCM的发现及其结构、光学和相变性质的表征正日益成为瓶颈。在该项目的支持下，中佛罗里达大学和麻省理工学院的研究人员开发了一种革命性的合成和表征范式，用于高通量发现和表征多组分PCM合金，专门为光学应用量身定制。他们不依赖于真空沉积，而是利用PCM解决方案的组合打印来促进高通量，可扩展的PCM合成，具有定制的化学物质，甚至复杂的多层结构。pcm打印在集成微加热器阵列上，作为多功能表征平台。它有助于系统地研究沉积后退火和operando表征对传统上难以评估的两个关键属性的影响：依赖温度的相变动力学和薄膜PCMs的光学常数。再加上其他与高通量筛选相匹配的表征技术，组合溶液处理为加速发现新的光学PCMs提供了一条便捷的途径，对节能数据通信、有源超材料、光子存储、反射显示、模拟光学计算等领域具有广泛影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical summaryPhase change materials (PCMs) are a class of compounds whose optical properties undergo dramatic changes upon micro-structural transformation. This unique property allows novel PCM-based reconfigurable or programmable optical systems to be created. Unlike conventional optics whose characteristics are fixed, the functions of such programmable optics can be dynamically configured on-the-fly to adapt to changing application needs. This project, supported by the Ceramics program in the Division of Materials Research, pioneers a transformative synthesis paradigm for expedited discovery of PCM alloys, specifically tailored for optical applications. Instead of relying on traditional costly vacuum systems to prepare PCMs, the program explores solution-based printing – similar to color printing of photos – as a scalable synthetic route of PCMs. The researchers also develop new methods to enable high-throughput screening and down-selection of PCMs to achieve material properties optimized for specific optical applications. Fundamental insights gained from this research have broad impacts on applications spanning energy-efficient data communications, active metamaterial, photonic memory, reflective display, analog optical computing, and beyond. In addition, the project also enables research opportunities for undergraduate students at the University of Central Florida and the Massachusetts Institute of Technology. Furthermore, the researchers develop a massive open online course (MOOC) dedicated to glass materials, thereby filling a critical gap when it comes to glass science education.Technical summaryPhase change materials (PCMs) are a class of compounds whose optical properties undergo dramatic changes upon micro-structural transformation. Discovery of new optical PCMs and characterization of their structural, optical, and phase transition properties, however, are increasingly becoming the bottleneck given the low throughput of traditional PCM synthesis and inability to reliably measure their properties in operando. With this project, supported by the Ceramics program in the Division of Materials Research, researchers at the University of Central Florida and the Massachusetts Institute of Technology develop a transformative synthesis and characterization paradigm for high-throughput discovery and characterization of multicomponent PCM alloys, specifically tailored for optical applications. Rather than relying on vacuum deposition, they harness combinatorial printing of PCM solutions to facilitate high-throughput, scalable synthesis of PCMs with custom chemistries and even complex multilayer structures. The PCMs are printed on integrated micro-heater arrays as a multifunctional characterization platform. It facilitates systematic investigation on the impact of post-deposition annealing and operando characterization of two critical attributes traditionally challenging to assess: temperature-dependent phase transition kinetics, and optical constants of thin film PCMs. Further coupled with a cohort of other characterization techniques commensurate with high-throughput screening, combinatorial solution processing presents a facile route for expedited discovery of new optical PCMs with broad impacts on energy-efficient data communications, active metamaterial, photonic memory, reflective display, analog optical computing, and beyond.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.