0000000000189659
AUTHOR
Benjamin Foerster
Momentum Distribution of Electrons Emitted from Resonantly Excited Individual Gold Nanorods.
Electron emission by femtosecond laser pulses from individual Au nanorods is studied with a time-of-flight momentum resolving photoemission electron microscope (ToF k-PEEM). The Au nanorods adhere to a transparent indium–tin oxide substrate, allowing for illumination from the rear side at normal incidence. Localized plasmon polaritons are resonantly excited at 800 nm with 100 fs long pulses. The momentum distribution of emitted electrons reveals two distinct emission mechanisms: a coherent multiphoton photoemission process from the optically heated electron gas leads to an isotropic emission distribution. In contrast, an additional emission process resulting from the optical field enhanceme…
CTAB Stabilizes Silver on Gold Nanorods
We present a study that allows us to explain the chemical changes behind the often observed but so far ununderstood drift of the plasmon resonance of chemically prepared gold nanorods in microfluid...
Particle Plasmons as Dipole Antennas: State Representation of Relative Observables
The strong interactions between light and plasmons (in metal nanoparticles) allow to observe chemical and physical processes on and around the particle on nanometer length scales as well as they al...
Interfacial States Cause Equal Decay of Plasmons and Hot Electrons at Gold-Metal Oxide Interfaces.
We compare the decay of plasmons and "conventional" hot electrons within the same series of gold/metal oxide interfaces. We found an accelerated decay of hot electrons at gold-metal oxide interfaces with decreasing band gap of the oxide material. The decay is accelerated by the increased phase space for electron scattering caused by additional interfacial states. Since plasmons decay faster within the same series of gold-metal oxide interfaces, we propose plasmons are able to decay into the same interfacial states as hot electrons. The similarity of plasmon damping to conventional hot electron decay implies that many classical surface analysis techniques and theoretical concepts are transfe…
Plasmon damping depends on the chemical nature of the nanoparticle interface
Damping of gold nanorod plasmons by surface-adsorbed molecules is best explained by scattering off adsorbate-induced dipoles.
Chemical Interface Damping Depends on Electrons Reaching the Surface.
Metallic nanoparticles show extraordinary strong light absorption near their plasmon resonance, orders of magnitude larger compared to nonmetallic nanoparticles. This "antenna" effect has recently been exploited to transfer electrons into empty states of an attached material, for example to create electric currents in photovoltaic devices or to induce chemical reactions. It is generally assumed that plasmons decay into hot electrons, which then transfer to the attached material. Ultrafast electron-electron scattering reduces the lifetime of hot electrons drastically in metals and therefore strongly limits the efficiency of plasmon induced hot electron transfer. However, recent work has revi…