Mid-infrared Intraband and Localized Surface Plasmon Resonance Spectroscopies of Doped Semiconductor Nanocrystals

化学系的大分子，超分子和纳米化学计划支持Masaru Kuno教授和他在圣母大学的研究小组研究半导体纳米晶体的光学性质。 分子和半导体纳米晶体与光反应，显示出独特的“指纹”，可用于识别。 Kuno教授的研究有助于开发新的分析检测技术，用于监测对健康，安全和国家安全至关重要的微量化学和生物物质。 了解半导体纳米晶体的基本光学性质也对手机中的低成本红外摄像头和可在室温下工作的红外探测器的开发具有影响。教授库诺和他的小组开发动手推广活动，如热成像套件，使兴趣低收入和少数民族学生在南本德社区学校系统在干职业。 最近的进展，在纳米晶体（NC）合成已经能够开发稳定的，自掺杂的半导体NC具有显着的掺杂密度。 这些NC表现出中红外带内和局部表面等离子体共振（LSPR）。 然而，很少有人了解它们对NC的大小，形状，表面化学和掺杂密度/掺杂剂活化的依赖性。 这是由于掺杂的NC系综中存在的不均匀性，这在当前的胶体NC合成中是不可避免的。 有限的手段存在进行高灵敏度，中红外光学测量的单个NC。 在化学系大分子，超分子和纳米化学计划的支持下，Kuno教授的研究团队解决了该领域的这一重要需求。 该研究小组采用了一种新开发的超分辨率红外吸收技术，称为红外光热外差成像（IR-PHI），以测量自掺杂NC的局部吸收。 这些测量，反过来，可以更好地了解这些半导体NC的基本属性和演变的带内跃迁到集体LSPR在高掺杂density.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

The Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry supports Professor Masaru Kuno and his research group at the University of Notre Dame to study the optical properties of semiconductor nanocrystals. Molecules and semiconductor nanocrystals react with light to exhibit unique "fingerprints" that can be used in their identification. Professor Kuno's research contributes to the development of new analytical detection technologies for monitoring trace amounts of chemical and biological substances that are important to health, safety, and national security. Understanding fundamental optical properties of semiconductor nanocrystals also has implications in the development of low cost infrared cameras in cellphones and infrared detectors that can operate at room temperature. Professor Kuno and his group develop hands-on outreach activities such as thermal imaging kits to bring interest lower income and minority students in the South Bend Community School system in STEM careers. Recent advances in nanocrystal (NC) synthesis have enabled the development of stable, self-doped semiconductor NCs with significant doping densities. These NCs exhibit mid-infrared intrabands and localized surface plasmon resonances (LSPRs). However, little is understood about their dependence on the NC size, shape, surface chemistry, and doping density/dopant activation. This is due to the inhomogeneities present in doped NC ensembles, which is unavoidable in current colloidal NC syntheses. Limited means exist for conducting highly sensitive, mid-infrared optical measurements of single NCs. With this support from the Macromolecular, Supramolecular, and Nanochemistry Program in the Chemistry Division, Professor Kuno’s research team addresses this important need in the field. The research team employs a newly developed, super-resolution infrared absorption technique, called infrared photothermal heterodyne imaging (IR-PHI), to measure the local absorption of self-doped NCs. These measurements, in turn, can enable better understanding of the fundamental properties of these semiconductor NCs and of the evolution of intraband transitions into collective LSPRs at high doping densities.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.