TY - JOUR U1 - Wissenschaftlicher Artikel A1 - Liu, Quan A1 - Ge, Dandan A1 - Wackenhut, Frank A1 - Coplin, Caitlin A1 - Cherqui, Charles A1 - Brecht, Marc A1 - Lin, Xiao-Min A1 - Schatz, George A1 - Schaller, Richard A1 - Adam, Pierre-Michel A1 - Bachelot, Renaud A1 - Meixner, Alfred T1 - Revealing the three-dimensional orientation and interplay between plasmons and interband transitions for single gold bipyramids by photoluminescence excitation pattern imaging JF - The journal of physical chemistry. C, Nanomaterials and interfaces N2 - Gold bipyramids (AuBPs) attract significant attention due to the large enhancement of the electric field around their sharp tips and well-defined tunability of their plasmon resonances. Excitation patterns of single AuBPs are recorded using raster-scanning confocal microscopy combined with radially and azimuthally polarized laser beams. Photoluminescence spectra (PL) and excitation patterns of the same AuBPs are acquired with three different excitation wavelengths. The isotropic excitation patterns suggest that the AuBPs are mainly excited by interband transitions with 488/530 nm radiation, while excitation patterns created with a 633 nm laser exhibit a double-lobed shape that indicates a single-dipole excitation process associated with the longitudinal plasmon resonance mode. We are able to determine the three-dimensional orientation of single AuBPs nonperturbatively by comparing experimental patterns with theoretical simulations. The asymmetric patterns show that the AuBPs are lying on the substrate with an out-of-plane tilt angle of around 10–15°. Y1 - 2021 SN - 1932-7447 SS - 1932-7447 U6 - https://doi.org/10.1021/acs.jpcc.1c08402 DO - https://doi.org/10.1021/acs.jpcc.1c08402 VL - 125 IS - 48 SP - 26978 EP - 26985 S1 - 8 PB - American Chemical Society CY - Washington D.C. ER -