Manufacturing of Ultra-stable Perovskite Nanoparticles for White Light Emitting Diodes

该项目旨在连续制造用于白色发光二极管（LED）的超稳定单分散钙钛矿纳米颗粒。用于连续生产纳米颗粒的常规微流体流动反应器不是一种可推广的方法，并且需要特定的实验条件来生长特定的纳米颗粒，并且通常导致纳米颗粒的尺寸和形状的不均匀性以及它们的不期望的聚集。该奖项支持基础研究，以开发一种强大的工艺，该工艺结合了两种类型的反应器，基于嵌段共聚物的纳米反应器和流动微反应器。该过程提供了独特的环境和能力，用于操纵流动微反应器内的纳米反应器内的前体的反应，这反过来又以可预测和连续的方式产生多功能纳米颗粒。 这些纳米颗粒可以单独开发，也可以作为自下而上组装纳米结构材料和具有理想特性的设备的构建模块，用于能源和生物医学应用，从而将基础科学发现转化为有益于社会的有用技术。该项目产生的知识广泛影响了连续生产各种单分散，超稳定，多功能纳米颗粒的稳健策略的开发，这些纳米颗粒不仅限于钙钛矿纳米颗粒，而且具有精确控制的尺寸和表面化学。该项目为研究生、本科生和高中生，包括妇女和代表性不足的少数民族，提供了接触纳米技术、纳米科学和纳米制造研究的机会。具体而言，绿色和红色发射铯铅溴化物和碘化物纳米粒子被选为钙钛矿纳米粒子在这项研究中，其有趣的光学性能的动机。这些纳米粒子是通过利用合理设计的星形嵌段共聚物作为流动微反应器内的纳米反应器来连续制作的。该方法通过双重保护赋予钙钛矿纳米颗粒的可扩展的纳米制造，其具有高均匀性和上级稳定性，即，用无机二氧化硅壳直接封端，然后用疏水性有机硅壳封端。该研究填补了在连续流动微反应器中对均匀钙钛矿纳米颗粒形成机理的深入理解的知识空白。研究团队计划设计基于具有明确分子量的两亲性星形嵌段共聚物的纳米反应器，制造大量不同组成的单分散超稳定钙钛矿纳米颗粒，探索有机硅封端和二氧化硅保护的核/壳纳米颗粒的稳定性，并使用钙钛矿纳米颗粒制造高性能白色LED。该奖项反映了NSF的法定使命，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来提供支持。

This project aims to continuously manufacture ultra-stable monodispersed perovskite nanoparticles for applications in white light-emitting diodes (LEDs). A conventional microfluidic flow reactor, used for continuous production of nanoparticles, is not a generalizable approach and requires specific experimental conditions for the growth of specific nanoparticles, and often results in non-uniformity in the size and shape of the nanoparticles as well as their undesirable aggregation. This award supports fundamental research for the development of a robust process that combines two types of reactors, block copolymer-based nanoreactors and a flow microreactor. This process provides a unique environment and capability for manipulating the reaction of precursors within the nanoreactors inside the flow microreactor, which, in turn, yields multifunctional nanoparticles in a predictable and continuous manner. These nanoparticles can be exploited either individually or as building-blocks for the bottom-up assembly of nanostructured materials and devices with desirable characteristics for use in energy and biomedical applications, thereby translating fundamental scientific discoveries into useful technologies that benefit society. Knowledge generated by this project broadly impacts the development of robust strategies for continuous production of a rich variety of monodispersed, ultra-stable, multifunctional nanoparticles, not limited to perovskite nanoparticles, with precisely controlled dimensions and surface chemistry. This project gives opportunities to graduate, undergraduate and high school students, including women and underrepresented minorities, to be exposed to nanocrystal, nanoscience and nanomanufacturing research. Specifically, green- and red-emitting cesium lead bromide and iodide nanoparticles are selected as perovskite nanoparticles in this study motivated by their intriguing optical properties. These nanoparticles are continuously crafted by capitalizing on rationally designed star-like block copolymers as nanoreactors inside a flow microreactor. This process imparts the scalable nanomanufacturing of perovskite nanoparticles with high uniformity and superior stabilities via a double protection, that is, direct capping with inorganic silica shell followed by hydrophobic organic silicone shell. This research fills the knowledge gap on the thorough understanding of the formation mechanism of uniform perovskite nanoparticles in a continuous-flow microreactor. The research team plans to design nanoreactors based on amphiphilic star-like block copolymers with well-defined molecular weights, manufacture a large amount of monodisperse ultra-stable perovskite nanoparticles of different compositions, explore the stabilities of silicone-capped and silica-protected core/shell nanoparticles, and fabricate high performance white LEDs using the perovskite nanoparticles.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.