CREST-Postdoctoral Research Fellowship: The Effects of Strong Confinement in the Ultrasmall Nanoparticle Regime on the Mechanism and Charge Transfer Rates in CdSe QDs

CREST-博士后研究奖学金：超小纳米颗粒体系中的强约束对 CdSe 量子点机制和电荷转移率的影响

• 批准号: 1914754
• 负责人: Megan Webster
• 金额: $ 20万
• 依托单位: Webster, Megan
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-15 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1914754&HistoricalAwards=false
• 关键词: CREST; Postdoctoral; Research; Fellowship; Effects

The Centers of Research Excellence in Science and Technology-Postdoctoral Research Fellowship (CREST-PRF) track within the CREST program supports beginning CREST Center investigators with significant potential and provides them with training and research experiences that will broaden perspectives, facilitate interdisciplinary interactions and establish them in positions of leadership within the scientific community. This CREST-PRF project is aligned with the research focus of the CREST Center for Interface Design and Engineered Assembly of Low Dimensional Structures (CREST-IDEALS) at the City College of New York. The goal of this research is understanding the optoelectronic properties of ultrasmall CdSe quantum dots (QDs). Quantum Dots are on the nano scale which results in optical and electronic properties that are different from larger particles. QDs have the potential to tap into the enormous potential of Solar Energy. The proposed work intends to investigate ultrasmall quantum dots synthesized by the researcher with x-ray spectroscopy and transmission electron microscopy techniques. These techniques will allow the researcher to more fully understand the ability of ultrasmall quantum dots to transfer charge and formulate a theoretical model to explain the behavior. This analysis will allow the incorporation of ultrasmall QDs into solar cell designs. Ultrasmall quantum dots display broad emission despite their monodispersity. Photoluminescence excitation (PLE) will allow for the investigation of which excitation wavelengths can cause the emission of a specified wavelength. Preliminary PLE data indicates that there are states within the bandgap to which direct absorption is possible. PLE data gathered from Qds will be compared to time resolved photoluminescence data (TRPL). The TRPL allows one to detect multiexponential decay systems, indicating that such systems have multiple lifetimes. Two acceptor species will be investigated with x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The acceptor species include a) molecules (ligands) of both e- donating and e- accepting character and b) carbon nanotubes (CNTs). The molecules will begin with investigating alkylthiols of varying chain length and benzene sulfonic monohydrate (BSAM). Qds will be embedded within CNTs as a means of not only charge transfer enhancement but also QD alignment for connectivity between QDs as well.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.

卓越研究中心在科学和技术博士后研究奖学金（CREST-PRF）的CREST计划内的轨道支持开始CREST中心研究人员具有显着的潜力，并为他们提供培训和研究经验，将拓宽视野，促进跨学科的互动，并建立他们在科学界的领导地位。 该CREST-PRF项目与纽约城市学院的CREST低维结构界面设计和工程组装中心（CREST-IDEALS）的研究重点一致。本研究的目的是了解超小型CdSe量子点（QD）的光电性能。量子点是纳米级的，这导致了与较大颗粒不同的光学和电子特性。 量子点有潜力利用太阳能的巨大潜力。 拟议的工作旨在研究由研究人员用x射线光谱和透射电子显微镜技术合成的超小量子点。这些技术将使研究人员能够更全面地了解超小量子点转移电荷的能力，并制定理论模型来解释这种行为。这种分析将允许将超小量子点纳入太阳能电池设计。超小量子点显示宽发射，尽管它们的单分散性。光致发光激发（PLE）将允许研究哪些激发波长可以引起特定波长的发射。初步PLE数据表明，有直接吸收的带隙内的状态是可能的。 将从Qds收集的PLE数据与时间分辨光致发光数据（TRPL）进行比较。TRPL允许人们检测多指数衰减系统，表明这种系统具有多个寿命。两种受体物种将研究与X射线光电子能谱（XPS）和透射电子显微镜（TEM）。受体物质包括a）具有供电子和受电子特性的分子（配体）和B）碳纳米管（CNT）. 分子将开始调查烷基硫醇的不同链长和苯磺酸一水合物（BSAM）。量子点将被嵌入碳纳米管中，不仅可以增强电荷转移，还可以使量子点之间的连接实现量子点对齐。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。