Open AccessExcitation of ultraviolet range Dirac-type plasmon resonance with an ultra-high Q-factor in the topological insulator Bi1.5Sb0.5Te1.8Se1.2 nanoshell
Author(s) -
Mingli Wan,
JianJun He,
Pengfei Ji,
Xiaopeng Zhang,
Mingli Tian,
Fengqun Zhou,
Erjun Liang
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.418514
Subject(s) - plasmon , nanoshell , surface plasmon resonance , surface plasmon , laser linewidth , topological insulator , resonance (particle physics) , localized surface plasmon , materials science , ultraviolet , optics , optoelectronics , physics , atomic physics , condensed matter physics , laser , nanoparticle , nanotechnology
Excitation of ultraviolet (UV) range plasmon resonance with high quality (Q)-factor has been significantly challenging in plasmonics because of inherent limitations in metals like Au and Ag. Herein, we theoretically investigated UV-visible range plasmons in the topological insulator Bi 1.5 Sb 0.5 Te 1.8 Se 1.2 (BSTS) nanosphere and nanoshell. In contrast to broad linewidth plasmon absorptions in the BSTS nanospheres, an ultra-sharp absorption peak with the Q-factor as high as 52 is excited at UV frequencies in the BSTS nanoshells. This peak is attributed to Dirac-type plasmon resonance originating from massless Dirac carriers in surface states of the BSTS. Furthermore, a tunable plasmon wavelength of the resonance is demonstrated by varying geometrical parameters of the BSTS nanoshells. This may find applications in surface enhanced Raman spectroscopies, nanolasers and biosensors in the UV regions.