New Photophysical and Photoelectrochemical Phenomena in Doped Nanocrystals

该研究由固态和材料化学计划支持，旨在开发新的胶体过渡金属掺杂半导体纳米晶体材料，这些材料显示出与先进信息处理、成像和能量转换技术相关的新的光物理和光谱电化学特性。将整合合成、分析和光谱技术，以发展对控制这些纳米晶体物理性质的结构/功能关系的基本理解。结合合成、光谱学、光谱电化学和分析方法的平衡研究工作将被应用于评估掺杂半导体纳米晶体中发光饱和的微观起源，非辐射衰减通道对掺杂半导体纳米晶体固有双发射的影响，双发射掺杂半导体纳米晶体探测等离子体微球温度的能力。研究了掺杂和未掺杂纳米晶体薄膜中电增亮的微观起源，利用电增亮识别和钝化纳米晶体表面特定电子或空穴陷阱的潜力，基于电增亮和电淬发光纳米晶体组合的多色电压可调发光薄膜的技术可行性，以及掺杂半导体纳米晶体中不同过渡金属氧化还原态的可及性。这项研究将产生新的基础科学见解，可以改变这些材料在各种技术中的理解和应用方式，包括信息处理、照明、生物成像和能量转换技术。掺杂半导体纳米结构在能量转换、能量存储和光催化技术以及信息处理和存储技术中无处不在，它们是许多未来器件技术的核心，包括自旋电子学领域。从这个项目中获得的信息将对这些技术都有广泛的影响。这项研究将解决在纳米尺度上由掺杂杂质的半导体制成的新形式的物质的发展。这个项目也将产生新的化学策略来控制掺杂纳米晶体的物理性质。除了提供新的基础科学见解和新的物质形式外，该项目还将为参与的本科生和研究生提供先进的技术培训，为他们未来在科学、工程和教育领域的职业生涯做好准备。特别的重点将放在整合本科生的研究和教育上，通过积极的本科生参与这项研究，将实验和概念纳入华盛顿大学的本科课程，接待来自本科院校的教师和学生作为华盛顿大学的访问科学家，并在西雅图地区的社区学院和高中开展成熟的推广活动。

TECHNICAL SUMMARYThis research supported by the Solid State and Materials Chemistry Program seeks to develop new colloidal transition-metal-doped semiconductor nanocrystalline materials that show new photophysical and spectroelectrochemical properties relevant to advanced information-processing, imaging, and energy conversion technologies. Synthetic, analytical, and spectroscopic techniques will be integrated to develop a fundamental understanding of the structure/function relationships that govern the physical properties of these nanocrystals. A balanced research effort incorporating synthetic, spectroscopic, spectroelectrochemical, and analytical approaches will be applied to evaluate the microscopic origins of luminescence saturation in doped semiconductor nanocrystals, the impact of nonradiative decay channels on the intrinsic dual emission of doped semiconductor nanocrystals, the capability of dual-emitting doped semiconductor nanocrystals to probe temperatures in plasmonic microspheres, the microscopic origins of electrobrightening in doped and undoped nanocrystal films, the potential to use electrobrightening for identifying and passivating specific electron or hole traps at nanocrystal surfaces, the technical feasibility of multi-color voltage tunable luminescent films based on combinations of electrobrightened and electroquenched luminescent nanocrystals, and the accessibility of different transition-metal redox states in doped semiconductor nanocrystals. This research will yield new fundamental scientific insights that could alter the ways such materials are understood and applied in various technologies including in information processing, lighting, bioimaging, and energy conversion technologies.NON-TECHNICAL SUMMARYDoped semiconductor nanostructures are ubiquitous in energy conversion, energy storage, and photocatalysis technologies, as well as in information processing and storage technologies, and they are central to numerous futuristic proposed device technologies including in the area of spin-based electronics. The information learned from this project will have broad implications for each of these technologies. This research will address the development of new forms of matter on nanometer length scales made from semiconductors doped with impurities. This project will also yield new chemical strategies for controlling the physical properties of doped nanocrystals. In addition to yielding new fundamental scientific insight and new forms of matter, this project will also provide advanced technical training for participating undergraduate and graduate students to prepare them for future careers in science, engineering, and education. Special emphasis will be placed on integrating research and education at the undergraduate level through aggressive involvement of undergraduates in this research, incorporation of experiments and concepts from this research into the University of Washington undergraduate curriculum, hosting faculty and students from undergraduate institutions as visiting scientists at University of Washington, and mature outreach activities at Seattle-area community colleges and high schools.