International Collaborations in Chemistry: Characterization of organically capped Si and group 14 alloy nanoparticle heterojunctions

该奖项由美国研究人员与德国同行之间的化学国际合作中化学部的大分子，超分子和纳米化学计划颁发，并由国际科学与工程办公室共同资助。获奖者是加州大学戴维斯分校的苏珊·考兹拉里奇教授。太阳能转换等应用面临着限制效率的设备架构方面的根本挑战。半导体纳米颗粒（NP）是目前太阳能转换的一个活跃的研究领域，具有可调的带隙到潜在的载流子倍增的好处。硅是感兴趣的半导体纳米粒子之一;然而，关于电子结构的性质仍然存在大量争论。特别是，表面氧化和界面终止在决定光学带隙和电子性质方面起着重要作用。Si（1-x）格克斯纳米颗粒的合成允许在不改变纳米颗粒尺寸的情况下系统地调节带隙。此外，关于典型地表现出带状电子结构的无机半导体和具有局域电子态的有机半导体之间的可逆电荷传输是否可以自由地发生的基本问题还没有回答。本计画的目标是研究矽或矽（1-x）格克斯合金的无机奈米粒子与空穴传导有机分子之间的电荷输运。 有机分子通过Si-C键共价键合到纳米颗粒表面。在这个p型系统中获得对电子传输过程的洞察与光化学有关。该项目的合成重点在于纳米颗粒的表面功能化。该项目的这一组成部分是美国合作伙伴项目的主题。 纯硅和硅锗合金纳米粒子具有很强的反应活性，其合成和表面化学是一个开放的研究领域。该项目的德国部分侧重于合成的有机封端纳米粒子的光电测量。该项目确保指导妇女和少数民族学生，并确保研究团队参与校园范围和全国范围的活动，如“农业、文学和科学本科研究人员奖学金”、“研究生教育和教授联盟”、STEM、与国家实验室合作联合培训学生、教学和外联活动。在加州大学戴维斯分校，代表性不足的本科生（MURPPS计划）和高中生（ACS SEED）被招募参加这项研究。国际交流活动包括两名研究生和三名本科生有机会与科隆大学的同龄人互动。

This award is made by the Macromolecular, Supramolecular and Nanochemistry program of the Chemistry Division within the International Collaboration in Chemistry between US investigators and their counterparts in Germany and is co-funded by the Office of International Science and Engineering. The recipient is Professor Susan Kauzlarich of the University of the California-Davis. Applications such as solar energy conversion are faced with fundamental challenges in device architecture that limit efficiencies. Semiconductor nanoparticles (NP) are currently an active area of research in solar energy conversion with the benefits of a tunable band gap to potential carrier multiplication. Silicon is one of the semiconductor NPs of interest; however, there is still a great deal of debate concerning the nature of the electronic structure. In particular, the surface oxidation and interface termination play an important role in determining the optical gap and electronic properties. Synthesis of Si(1-x)Gex NPs allows for systematic tuning of the bandgap without changing size of the NP. In addition, the fundamental question concerning whether reversible charge transport between inorganic semiconductors typically exhibiting a band-like electronic structure and organic semiconductors featuring localized electronic states can take place freely is unanswered. The goal of this project is to study charge transport between inorganic nanoparticles of Si or Si(1-x)Gex alloys and hole-conducting organic molecules. The organic molecules are covalently bonded to the nanoparticle surface via Si-C bonds. Gaining insight on the electron transport process in this p-type system is relevant to photovoltaics. The synthesis focus of the project resides on the surface functionalization of the nanoparticles. This component of the project is the theme of the US partner's project. Pure Si and Si-Ge alloyed nanoparticles are very reactive and their synthesis and surface chemistry are opened fields of study. The German component of the project focuses on optoelectronic measurements of the synthesized organo-capped nanoparticles. The project ensures mentoring women and minority students and participation of the research team in campus-wide and nation-wide activities such as "Memberships for Undergraduate Researchers in Agriculture, Letters, and Science" (MURALS), "Alliance for Graduate Education and the Professoriate" (AGEP), STEM, collaboration with National Laboratories for joint training of students, teaching, and outreach activities. At UC Davis, underrepresented undergraduates (MURPPS program) and high school students (ACS SEED) are recruited to participate in this research. International exchange activities include two graduate students and three undergraduates having the opportunity to interact with peers at the University of Cologne.