Plasmonic evolution of atomically size-selected Au clusters by electron energy loss spectrum

Siqi Lu; Lin Xie; Kang Lai; Runkun Chen; Lu Cao; Kuojuei Hu; Xuefeng Wang; Jinsen Han; Xiangang Wan; Jianguo Wan; Qing Dai; Fengqi Song; Jiaqing He; Jiayu Dai; Jianing Chen; Zhenlin Wang; Guanghou Wang

doi:10.1093/nsr/nwaa282

Plasmonic evolution of atomically size-selected Au clusters by electron energy loss spectrum

Natl Sci Rev. 2020 Nov 25;8(12):nwaa282. doi: 10.1093/nsr/nwaa282. eCollection 2021 Dec.

Authors

Siqi Lu¹, Lin Xie², Kang Lai³, Runkun Chen⁴, Lu Cao¹, Kuojuei Hu¹, Xuefeng Wang⁵, Jinsen Han³, Xiangang Wan¹, Jianguo Wan¹, Qing Dai⁶, Fengqi Song¹, Jiaqing He², Jiayu Dai³, Jianing Chen⁴, Zhenlin Wang¹, Guanghou Wang¹

Affiliations

¹ National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China.
² Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
³ Department of Physics, National University of Defense Technology, Changsha 410073, China.
⁴ Institute of Physics, Chinese Academy of Sciences and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China.
⁵ School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
⁶ Division of Nanophotonics, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.

Abstract

The plasmonic response of gold clusters with atom number (N) = 100-70 000 was investigated using scanning transmission electron microscopy-electron energy loss spectroscopy. For decreasing N, the bulk plasmon remains unchanged above N = 887 but then disappears, while the surface plasmon firstly redshifts from 2.4 to 2.3 eV above N = 887 before blueshifting towards 2.6 eV down to N = 300, and finally splitting into three fine features. The surface plasmon's excitation ratio is found to follow N ^0.669, which is essentially R ². An atomically precise evolution picture of plasmon physics is thus demonstrated according to three regimes: classical plasmon (N = 887-70 000), quantum confinement corrected plasmon (N = 300-887) and molecule related plasmon (N < 300).

Keywords: atomically precise; electron energy loss spectroscopy; full-scale evolution; gold cluster; plasmonic response.