Single Particle Spectroscopy and Microscopy of Doped Colloidal Semiconductor Nanocrystals

掺杂胶体半导体纳米晶体的单粒子光谱和显微镜

• 批准号: 1904847
• 负责人: Todd Krauss
• 金额: $ 47.35万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904847&HistoricalAwards=false
• 关键词: Single; Particle; Spectroscopy; Microscopy; Doped

Semiconductor nanocrystals are small, crystalline particles that contain only hundreds to thousands of atoms. At these small sizes, new optical and electronic properties emerge, which can be adjusted by changing the particle's size and shape. These properties can also be manipulated by swapping just a few atoms in the crystal lattice with atoms of another element, or dopant. The precise control over the number and placement of these dopant atoms within a nanocrystal is challenging. With support from the Macromolecular, Supramolecular and Nanochemistry program in the Chemistry Division, Professor Todd Krauss and his students at the University of Rochester are using sophisticated microscopy methods to correlate the number and position of dopants in a single nanocrystal with their luminescent and electronic properties. Their discoveries could have important implications for designing nanocrystals used in emerging technologies that range from solar energy conversion to quantum information systems. The project is also training the next generation of scientists in the development and application of advanced experimental physical chemistry methods. The team is introducing the project research to the public and fostering an enthusiasm for scientific discovery through outreach efforts at the Rochester Museum and Science Center and other public venues. The project is developing the detailed understanding of nanocrystal doping and doping mechanisms needed to synthesize nanocrystals and nanocrystal assemblies with improved chemical and photophysical properties. Studies of silver cation (Ag+)-doped cadmium selenide (CdSe) nanocrystals and nanoplatelets are uncovering the specific chemical mechanisms occurring during the doping process. State-of-the-art electrostatic force microscopy measurements in combination with simultaneous measurements of photoluminescence from a single nanocrystal reveal how impurity atoms change the electronic and optical properties of the intrinsic nanoparticle. The project is also investigating the optical properties of tin telluride (SnTe) nanocrystals. This emerging direct-bandgap material could be used as an environmentally friendly alternative to current materials in infrared-based technologies. However, the basic properties of the SnTe excited state (e.g. electronic, excitonic, or plasmonic) remain unknown. Steady-state and time-resolved spectroscopies are used in conjunction with high-resolution electron microscopies to correlate photophysical observations with material composition to develop a detailed picture of the SnTe excited state.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.

半导体纳米晶体是小的晶体颗粒，仅包含数百至数千个原子。在这些小尺寸下，出现了新的光学和电子特性，可以通过改变颗粒的尺寸和形状来调整。这些性质也可以通过将晶格中的几个原子与另一种元素或掺杂剂的原子交换来操纵。精确控制这些掺杂剂原子的数量和位置是具有挑战性的。在化学系大分子、超分子和纳米化学项目的支持下，罗切斯特大学的托德·克劳斯教授和他的学生们正在使用复杂的显微镜方法，将单个晶体中掺杂剂的数量和位置与它们的发光和电子特性相关联。他们的发现可能对设计用于从太阳能转换到量子信息系统的新兴技术的纳米晶体具有重要意义。该项目还在开发和应用先进的实验物理化学方法方面培训下一代科学家。 该团队正在向公众介绍该项目研究，并通过在罗切斯特博物馆和科学中心以及其他公共场所的外展工作来培养对科学发现的热情。该项目正在发展对纳米掺杂和掺杂机制的详细理解，以合成具有改进的化学和物理特性的纳米晶体和纳米组装体。对银离子掺杂的硒化镉纳米晶和纳米片的研究揭示了掺杂过程中发生的特定化学机制。国家的最先进的静电力显微镜测量结合从一个单一的纳米粒子的光致发光的同时测量揭示杂质原子如何改变本征纳米粒子的电子和光学性质。该项目还在研究碲化锡（SnTe）纳米晶体的光学特性。这种新兴的直接带隙材料可以用作基于红外技术的现有材料的环境友好型替代品。然而，SnTe激发态的基本性质（例如电子、激子或等离子体）仍然未知。 稳态和时间分辨光谱法与高分辨率电子显微镜结合使用，将光物理观察与材料成分相关联，以获得SnTe激发态的详细图像。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值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

Elucidating the neuropathophysiology of COVID-19 using quantum dot biomimetics of SARS-CoV-2

• DOI: 10.1117/12.2609118
• 发表时间: 2022-03
• 作者: W. Chiang;J. Urban;Angela Litzburg;B. Nilsson;H. Gelbard;Todd D. Krauss

Quantum Dots for Improved Single-Molecule Localization Microscopy.

• DOI: 10.1021/acs.jpcb.0c11545
• 发表时间: 2021-03-18
• 期刊: The journal of physical chemistry. B
• 作者: Urban JM;Chiang W;Hammond JW;Cogan NMB;Litzburg A;Burke R;Stern HA;Gelbard HA;Nilsson BL;Krauss TD
• 通讯作者: Krauss TD