Determining hot-carrier transport dynamics from terahertz emission

• 成果类型: Article
• 署名作者: Taghinejad, Mohammad; Xia, Chenyi; Hrton, Martin; Lee, Kyu-Tae; Kim, Andrew S.; Li, Qitong; Guzelturk, Burak; Kalousek, Radek; Xu, Fenghao; Cai, Wenshan; Lindenberg, Aaron M.; Brongersma, Mark L.
• 署名单位: Stanford University; Stanford University; Brno University of Technology; Brno University of Technology; University System of Georgia; Georgia Institute of Technology; United States Department of Energy (DOE); Argonne National Laboratory; University System of Georgia; Georgia Institute of Technology; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10033
• DOI: 10.1126/science.adj5612
• 发表日期: 2023-10-20
• 页码: 299-305
• 关键词: electron dynamics; energy-distributions; light; photodetection; thermalization; generation; device

摘要

Understanding the ultrafast excitation and transport dynamics of plasmon-driven hot carriers is critical to the development of optoelectronics, photochemistry, and solar-energy harvesting. However, the ultrashort time and length scales associated with the behavior of these highly out-of-equilibrium carriers have impaired experimental verification of ab initio quantum theories. Here, we present an approach to studying plasmonic hot-carrier dynamics that analyzes the temporal waveform of coherent terahertz bursts radiated by photo-ejected hot carriers from designer nano-antennas with a broken symmetry. For ballistic carriers ejected from gold antennas, we find an similar to 11-femtosecond timescale composed of the plasmon lifetime and ballistic transport time. Polarization- and phase-sensitive detection of terahertz fields further grant direct access to their ballistic transport trajectory. Our approach opens explorations of ultrafast carrier dynamics in optically excited nanostructures.