气候变化领域集成服务门户(CCPortal): Ultrafast nanometric imaging of energy flow within and between single carbon dots

CCPortal

DOI	10.1073/pnas.2023083118
	Ultrafast nanometric imaging of energy flow within and between single carbon dots
	Nguyen H.A.; Srivastava I.; Pane D.; Gruebele M.
发表日期	2021
ISSN	00278424
卷号	118 期号:11
英文摘要	Time- and space-resolved excited states at the individual nanoparticle level provide fundamental insights into heterogeneous energy, electron, and heat flow dynamics. Here, we optically excite carbon dots to image electron-phonon dynamics within single dots and nanoscale thermal transport between two dots. We use a scanning tunneling microscope tip as a detector of the optically excited state, via optical blocking of electron tunneling, to record movies of carrier dynamics in the 0.1-500-ps time range. The excited-state electron density migrates from the bulk to molecularscale (∼1 nm2) surface defects, followed by heterogeneous relaxation of individual dots to either long-lived fluorescent states or back to the ground state. We also image the coupling of optical phonons in individual carbon dots with conduction electrons in gold as an ultrafast energy transfer mechanism between two nearby dots. Although individual dots are highly heterogeneous, their averaged dynamics is consistent with previous bulk optical spectroscopy and nanoscale heat transfer studies, revealing the different mechanisms that contribute to the bulk average. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Carbon dots; Femtosecond imaging; Single-particle dynamics; SMA-STM; Transient absorption
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180232
作者单位	Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, United States; Department of Diagnostic Radiology and Nuclear Medicine, Center for Blood Oxygen Transport & Hemostasis (CBOTH), University of Maryland, Baltimore, MD 21201, United States; Department of Pediatrics, University of Maryland, Baltimore, MD 21201, United States; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
推荐引用方式 GB/T 7714	Nguyen H.A.,Srivastava I.,Pane D.,et al. Ultrafast nanometric imaging of energy flow within and between single carbon dots[J],2021,118(11).
APA	Nguyen H.A.,Srivastava I.,Pane D.,&Gruebele M..(2021).Ultrafast nanometric imaging of energy flow within and between single carbon dots.Proceedings of the National Academy of Sciences of the United States of America,118(11).
MLA	Nguyen H.A.,et al."Ultrafast nanometric imaging of energy flow within and between single carbon dots".Proceedings of the National Academy of Sciences of the United States of America 118.11(2021).