Excitation Enhancement of a Quantum Dot Coupled to a Plasmonic Antenna

Plasmonic antennas are key elements to control the luminescence of quantum emitters. However, the antenna's influence is often hidden by quenching losses. Here, the luminescence of a quantum dot coupled to a gold dimer antenna is investigated. Detailed analysis of the multiply excited states quantifies the antenna's influence on the excitation intensity and the luminescence quantum yield separately

Real-space mapping of tailored sheet and edge plasmons in graphene nanoresonators

Plasmons in graphene nanoresonators have many potential applications in photonics and optoelectronics, including room-temperature infrared and terahertz photodetectors, sensors, reflect arrays or modulators1, 2, 3, 4, 5, 6, 7. The development of efficient devices will critically depend on precise knowledge and control of the plasmonic modes. Here, we use near-field microscopy8, 9, 10, 11 between λ0 = 10–12 μm to excite and image plasmons in tailored disk and rectangular graphene nanoresonators, and observe a rich variety of coexisting Fabry–Perot modes. Disentangling them by a theoretical analysis allows the identification of sheet and edge plasmons, the latter exhibiting mode volumes as small as 10−8λ03. By measuring the dispersion of the edge plasmons we corroborate their superior confinement compared with sheet plasmons, which among others could be applied for efficient 1D coupling of quantum emitters12. Our understanding of graphene plasmon images is a key to unprecedented in-depth analysis and verification of plasmonic functionalities in future flatland technologies.Peer ReviewedPostprint (author's final draft

Polarized nonlinear nanoscopy of metal nanostructures

International audienc

Flash Infrared Pulse Time Control of Perovskite Crystal Nucleation and Growth from Solution

Flash infrared annealing (FIRA) of perovskite films enables manufacturing compact perovskite layers for photovoltaic devices. Here, a variable infrared pulse length to control crystal nucleation and growth in perovskite films is investigated. By varying the FIRA parameters, high-quality films are fabricated of fully inorganic and hybrid perovskites. Furthermore, film characterizations are analyzed for each FIRA protocol, unveiling the nature of the film growth. This demonstrates the versatility of FIRA and establishes it as a fast synthesis process, which provides detailed control over the perovskite morphology and crystallinity

Polarized nonlinear nanoscopy of metal nanostructures

International audienceNonlinear signals from metal nanostructures are known to be highly polarization-dependent, due to the intrinsic vectorial nature of nonlinear optical coupling. Nonlinear optical polarization responses contain important information on the near-field properties of nanostructures; however they remain complex to monitor and to model at the nano-scale. Polarization resolved nonlinear optical microscopy can potentially address this question, however the recorded signals are generally averaged over the diffraction-limited size of a few hundreds of nanometers, thus missing the spatial specificity of the nanostructure's optical response. Here we present a method of polarized nanoscopy that exploits sub-diffraction resolution information down to a few tens of nanometer. Even though the resulting image is diffraction-limited, the information gained by polarization-induced modulation provides a higher level of selectivity that is directly related to vectorial optical responses at a scale below the diffraction limit. We show that polarized nonlinear nanoscopy permits to spatially map the vectorial nature of plasmonic nonlinear optical interactions in nanostructures

Efficient single particle detection with a superconducting nanowire

Detection of ?- and ?-particles is of paramount importance in a wide range of applications. Current particle detectors are all macroscopic and have limited time resolution. We demonstrate a nanoscale particle detector with a small detection volume, high detection efficiency, short dead times and low dark count levels. We measure ?- and ?-particle detection efficiencies close to unity using different sources and also demonstrate blindness towards ?-rays. Our nanoscale detector offers particle detection measurements with unprecendented spatial resolution.Quantum NanoscienceApplied Science

Characterization of gold nanostructures using polarized nonlinear microscopy

International audienc

Nanopatterned CoPt alloys with perpendicular magnetic anisotropy

International audienc

Light-Assisted Solvothermal Chemistry Using Plasmonic Nanoparticles

Solvothermal synthesis, denoting chemical reactions occurring in metastable liquids above their boiling point, normally requires the use of a sealed autoclave under pressure to prevent the solvent from boiling. This work introduces an experimental approach that enables solvothermal synthesis at ambient pressure in an open reaction medium. The approach is based on the use of gold nanoparticles deposited on a glass substrate and acting as photothermal sources. To illustrate the approach, the selected hydrothermal reaction involves the formation of indium hydroxide microcrystals favored at 200 °C in liquid water. In addition to demonstrating the principle, the benefits and the specific characteristics of such an approach are investigated, in particular, the much faster reaction rate, the achievable spatial and time scales, the effect of microscale temperature gradients, the effect of the size of the heated area, and the effect of thermal-induced microscale fluid convection. This technique is general and could be used to spatially control the deposition of virtually any material for which a solvothermal synthesis exists. © 2016 American Chemical Society

Maßgeschneiderte Nano-Komponenten: Herstellung und Funktionalisierung (MANAKO) : Abschlussbericht : Berichtszeitraum: 01.07.2007 - 30.11.2008

[no abstract available