Tunable plasmon resonances in suspended 2D molybdenum oxide flakes are demonstrated. The configuration generates a large depolarization factor and the presence of ultra-doping produces visible-light resonances. process is conducted by reducing semiconducting MoO3 using simulated solar irradiation. generated can be controlled doping levels flakes' lateral dimensions, as well exposure to model protein.

We report a facile and robust synthesis of CdxZn1–xS graded shells on CdSe nanoparticles that are prepared by interface alloying between CdS ZnS at elevated temperatures. Alloying provides systematic control over the electronic structure enables switching Type-I quasi-Type-II configurations. Good particle shape, shell thickness, composition is achieved slowly adding zinc oleate octane thiol via syringe pump to readily CdSe/CdS particles. The resultant quantum dots exhibit PL yields up 97%...

Energy transfer from quantum dots (QDs) to variable-length, dye-labeled peptides is reported. We find that existing models used calculate the efficiency of energy steady-state measurements are insufficient for nanoparticle–dye interactions. To accurately measure distance dependence as a function separation, effects both multiple valencies and variations in luminescence yield acceptor dye with separation need be taken into consideration. Using Poisson statistics, we account distribution...

The role of interface sharpness in controlling the excited state dynamics CdSe/ZnSe core/shell particles is examined here. Particles composed with 2.4–4.0 nm diameter cores and approximately 4 monolayer shells are synthesized at relatively low temperature, ensuring a sharp core–shell interface. Subsequent annealing results cadmium zinc interdiffusion, softening TEM imaging absorption spectra reveal that no change particle sizes. Annealing 5–10 blue shift spectrum, which compared to...

Metal nanostructures have found extensive use in a variety of applications chemistry, including as substrates for molecular sensing and surface enhanced spectroscopy nanoscale heaters photothermal therapy. These depend on the strong absorption field enhancements associated with localized plasmon resonance (LSPR). This has led to number studies how LSPR line width, which measures energy losses coherent electron motion, depends size shape different types metal nanoparticles, environment around...

The interaction between plasmonic and excitonic systems the formation of hybridized states is an area intense interest due to potential create exotic light-matter states. We report herein coupling leaky surface plasmon polariton (SPP) modes single Ag nanowires excitons a cyanine dye (TDBC) in open nanocavity. Silver were spin-cast onto glass coverslips, wavevector SPP mode was measured by back focal plane (BFP) microscopy. Performing these measurements at different wavelengths allows...

Energy transfer from the defect state of zinc oxide nanoparticles to fluorescent dye AlexaFluor 594 (A594) cadaverine has been studied using both steady-state and time-resolved photoluminescence (PL) measurements. The addition five stoichiometric equivalents A594 completely quenches visible emission nano crystals. We also find that entire ZnO is reduced without any change in overall line shape emission, demonstrating a single electronic coupled phonon modes crystal lattice. energy modeled...

Brillouin oscillations, which are GHz frequency waves that arise from the interaction of light with acoustic waves, experiencing increasing applications in biology and materials science. They provide information about speed sound refractive index material they propagate in, have recently been used imaging applications. In current study, oscillations observed through ultrafast transient reflectivity measurements using chemically synthesized Au nanoplates as opto-acoustic transducers. The...

Metal nanostructures display several types of resonances. In the visible and near-IR spectral regions, there are localized surface plasmon resonances (LSPRs) that involve coherent oscillation conduction electrons. Extended metal nanostructures, such as nanowires or nanoplates, also exhibit propagating polaritons (PSPPs), which motions electrons at structure have a well-defined momentum. addition, vibrational normal modes give rise to low frequency in gigahertz terahertz range. These...

Zinc oxide nanocrystals were prepared in ethanol and spin-cast to form semiconductor nanocrystal thin films that thermally annealed at temperatures between 100 800 °C. Particle size, monodispersity, film porosity determined by X-ray diffraction, ultraviolet−visible absorption spectroscopy, spectroscopic ellipsometry, respectively. Film rapidly decreased above 400 °C, from 32% 26%, which coincided with a change electronic properties. Above the ZnO electron mobility, FET transfer...

The mechanical resonances of metal nanostructures are strongly affected by their environment. In this paper the way breathing modes single nanowires damped liquids with different viscosities was studied ultrafast pump-probe microscopy experiments. Both supported on a glass substrate and suspended over trenches were investigated. measured quality factors for liquid damping in good agreement continuum mechanics calculations an inviscid fluid that assume continuity stress displacement at...

Transient absorption microscopy (TAM) measurements have been used to study the optical properties of surface plasmon polariton (SPP) modes in gold nanoplates on a glass substrate. For thin nanoplates, TAM images show an oscillation signal across plate due interference between "bound" and "leaky" SPP modes. The wavelength pattern is given by λ = 2π/Δk, where Δk difference wavevectors for bound leaky sensitive dielectric constant material above nanoplate. Back focal plane imaging was also...

Adv. Mater. 2014, 26, 3931–3937 The spelling of the name author Nikhil V. Medhekar is hereby corrected. was incorrect in article as originally published.

Femtosecond laser excitation of strongly absorbing thin films generates picosecond acoustic waves in the surrounding medium. In time-domain transient absorption experiments, these can give rise to Brillouin oscillations. this contribution, attenuation oscillations microscopy experiments has been investigated for different and detection conditions. The results show that measured constants depend on numerical aperture (NA) microscope objective used with higher NA objectives giving larger...

Propagating surface plasmon polaritons (PSPPs) are electron motions at the surfaces of conductors that have a definite momentum. For metal nanostructures on glass substrate, two types PSPP modes exist: bound where field is localized metal–glass interface and leaky metal–air interface. In this paper, Ag Au nanostripes created by photolithography were examined combination real space Fourier (back focal plane) imaging measurements finite element simulations. The back plane images provide...

Exciton-polariton condensation in direct bandgap semiconductors strongly coupled to light enables a broad range of fundamental studies and applications like low-threshold electrically driven lasing. Yet, materials hosting exciton-polariton ambient conditions are rare, with fabrication protocols that often inefficient non-scalable. Here, room-temperature lasing is observed microcavity embedded formamidiniumlead bromide (FAPbBr$_3$) perovskite film. This optically active material spin-coated...

The remarkable electrical, optical and mechanical properties of graphene make it a desirable material for electronics, optoelectronics quantum applications. A fundamental understanding the electrical conductivity across wide frequency range is required development such technologies. In this study, we use terahertz (THz) time-domain spectroscopy to measure complex dynamic electrostatically gated graphene, in broad $\sim$0.1 - 7 THz range. doped follows conventional Drude model, predominantly...