Using surface plasmonics to turn on fullerene's dark excitons

Article

关键词: ELECTRON-HOLE EXCITATIONS;    LEVEL ALIGNMENT;    GREENS-FUNCTION;    C-60;    SPECTRA;    SEMICONDUCTORS;    MOLECULES;    RESONANCE;    C60;   

DOI  :  10.1103/PhysRevB.89.195433

来源: SCIE

【 摘 要 】

Using our recently proposed Bethe-Salpeter G(0)W(0) formulation, we explore the optical absorption spectra of fullerene (C-60) near coinage metal surfaces (Cu, Ag, and Au). We pay special attention to how the surface plasmon omega(s) influences the optical activity of fullerene. We find that the lower- energy fullerene excitons at 3.77 and 4.8 eV only weakly interact with the surface plasmon. However, we find that the surface plasmon strongly interacts with the most intense fullerene pi exciton, i.e., the dipolar mode at (h) over bar omega(+) approximate to 6.5 eV, and the quadrupolar mode at (h) over bar omega(-) approximate to 6.8 eV. When fullerene is close to a copper surface (z(0) approximate to 5.3 angstrom), the dipolar mode omega(+) and localized surface plasmons in the molecule/surface interface hybridize to form two coupled modes which both absorb light. As a result, the molecule gains an additional optically active mode. Moreover, in resonance, when omega(s) approximate to omega(+/-), the strong interaction with the surface plasmon destroys the omega(-) quadrupolar character and it becomes an optically active mode. In this case, the molecule gains two additional very intense optically active modes. Further, we find that this resonance condition omega(s) approximate to omega(+/-), is satisfied by silver and gold metal surfaces.

【 授权许可】

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