CAREER: New Models for Controlling InP Nucleation, Growth, and Luminescence using Magic-Sized Clusters and Targeted Surface Chemistry

现代社会的标志之一是高效地将能源从一种形式转化为另一种形式，这使得人类生产力得以提高，并有助于经济发展。随着技术的成熟，这方面的不断进步需要开发具有新的和改进的功能的新材料。由于纳米材料的突发性和尺寸依赖性，预计它们将极大地塑造下一代能源技术的未来。纳米材料的功能依赖于科学家获得具有均匀和精确原子结构的材料的能力。这是一个巨大的挑战，因为纳米材料包含数百到数千个原子，即使是几个原子错位也会显着改变它们的功能。根据这一职业奖进行的研究旨在解决以原子级别的精度控制纳米材料的组成和界面方面的根本挑战。这项研究的全球相关性被用来推进该项目的主要教育目标，即：1)在华盛顿大学(UW)创建能源化学本科专业，2)与华盛顿大学Phi Lambda Upsilon(国家化学荣誉学会)分会合作，开发以胶体纳米科学为主题的动手演示材料和研讨会，以及3)通过与化学女性导师网络、UW女性化学科学、该奖项的科学目标是了解磷化铟(InP)和相关的胶体量子点(QD)是如何在溶液中成核和生长的，以及如何利用表面化学合理地修改这一机制和所得到的纳米晶体的性质。作为迈向这一目标的一步，启动了几个主题，以提供实验环境，在其中可以研究这些材料中的成核、生长和光致发光调制。这些包括：1)使用可分离的、结构表征的和原子上精确的魔术大小的团簇中间体测试InP成核的新模型；2)了解表面化学如何影响InP魔术大小的团簇的结构和功能，以获得各向异性形状控制和掺杂的一般策略；以及3)发现新的合成后表面化学，利用Lewis酸配位化学来开启InP和相关量子点的发光并对其进行颜色调节。研究方法主要集中在开发新的假设驱动的合成方法，以及这些材料的性质和电子结构的光谱和理论表征。利用与时间相关电子结构理论、X射线结晶学和X射线光电子能谱专家的持续合作，帮助回答基本的结构和机制问题。教育部分涉及需要培训下一代科学家和工程师，通过开发相关和适用的讲课材料、学习工具和演示，解决科学上的重大挑战。

One of the hallmarks of modern society has been efficiently and effectively transforming energy from one form to another, which has enabled increased human productivity and aided economic development. As technologies mature, continued progress on this front requires developing new materials with new and improved function. As a result of their emergent, size-dependent properties, nanomaterials are forecasted to significantly shape the future of next generation energy technologies. Nanomaterial function relies on the ability of scientists to access these materials with uniform and precise atomic structures. This is an enormous challenge since nanomaterials contain hundreds to thousands of atoms and even a few atoms out of place can significantly alter their function. Research conducted under this CAREER award aims to address the fundamental challenges in controlling the composition and interfaces of nanomaterials with atom-level precision. The globally-relevant nature of this research is leveraged to advance the major educational goals of this project, namely to: 1) create an undergraduate specialization in Chemistry for Energy at the University of Washington (UW), 2) develop hands-on demonstration materials and workshops on the topic of colloidal nanoscience targeted to middle and high school students in collaboration with the UW Phi Lambda Upsilon (National Chemistry Honor Society) chapter, and 3) broaden participation in chemistry at the undergraduate, graduate and professional level through work with the Chemistry Women Mentorship Network, the UW Women in Chemical Sciences, and the NSF-supported Louis Stokes Alliance for Minority Participation program.The scientific goal of this award is to understand how indium phosphide (InP) and related colloidal quantum dots (QDs) nucleate and grow in solution and how to rationally modify that mechanism and the properties of the resulting nanocrystals using surface chemistry. As a step toward this goal, several themes are initiated to provide the experimental context in which nucleation, growth, and photoluminescence modulation in these materials can be studied. These include: 1) testing new models of InP nucleation using isolable, structurally characterized and atomically precise magic-sized cluster intermediates; 2) understanding how surface chemistry impacts the structure and function of InP magic-sized clusters to gain access to general strategies for anisotropic shape control and doping; and 3) discovering new post-synthetic surface chemistry to turn-on and color-tune the luminescence of InP and related QDs using Lewis acid coordination chemistry. The research approach focuses primarily on the development of new hypothesis-driven synthetic methods as well as spectroscopic and theoretical characterization of the properties and electronic structure of these materials. Ongoing collaborations with experts in time-dependent electronic structure theory, X-ray crystallography, and X-ray photoelectron spectroscopy are leveraged to help answer fundamental structural and mechanistic questions. The educational component addresses the need to train the next generation of scientists and engineers to solve scientific grand challenges through the development of relevant and applicable lecture materials, learning tools and demonstrations.