Streaked photoemission from nanostructures is characterized by size-and material-dependent nanometer-scale variations of the induced nanoplasmonic response to the electronic field of the streaking pulse and thus holds promise of allowing photoelectron imaging with both subfemtosecond temporal and nanometer spatial resolution. In order to scrutinize the driven collective electronic dynamics in 10-200-nm-diameter gold nanospheres, we calculated the plasmonic field induced by streaking pulses in the infrared and visible spectral range and developed a quantum-mechanical model for streaked photoemission by extreme ultraviolet pulses. Our simulated photoelectron spectra reveal a significant amplitude enhancement and phase shift of the photoelectron streaking trace relative to calculations that exclude the induced plasmonic field. Both are most pronounced for streaking pulses tuned to the plasmon frequency and retrace the plasmonic electromagnetic field enhancement and phase shift near the nanosphere surface. DOI: 10.1103/PhysRevA.94.051401 Recent advances in nanoscience and nanotechnologies are creating new avenues for designing and making nanometerscale metal structures which respond to irradiation with electromagnetic radiation by creating a tunable induced electric field near the metal surface [1,2]. This induced "plasmonic" field originates in the incident-field-driven coherent collective motion of conduction electrons which, when stimulated near its natural resonance (plasmon) frequency, generate a very large induced polarization in subwavelength-size structures on substrate surfaces [3-9] and isolated nanoparticles [10]. Near metallic nanospheres and for linearly polarized incident radiation [10][11][12][13][14][15][16], the oscillating induced polarization gives rise to oscillating plasmonic fields with dipole-like angular distribution oriented along the polarization direction of the incident radiation [17].Strong plasmonic field enhancement effects are linked to the local dielectric properties of the nanostructure and form the underlying physical phenomenon in established surfaceenhanced Raman spectroscopy (SERS) [18] and various prototype and suggested applications, such as attosecond nanoplasmonic-field microscopy [3] and nanoplasmonically enhanced photocatalysis [19] and light harvesting [20]. The detailed understanding of plasmonic excitations in solids requires imaging techniques that resolve their spatiotemporal evolution [3,16]. While ultrafast laser technology is available in many laboratories worldwide, allowing the resolution of various aspects of the electronic dynamics during the infrared (IR)-pulse-streaked extreme ultraviolet (XUV) photoionization of gaseous atoms with a precision of about 10 as [21], a promising emerging line of attosecond science targets the electronic dynamics in solids, biomolecules, and nanostructures [2,22]. These highly time-resolved investigations on solid targets address effects that are absent in isolated atoms in the gas phase, such as the propagation of photoexcite...

We propose a scheme for the reconstruction of plasmonic near fields at isolated nanoparticles from infrared-streaked extreme-ultraviolet photoemission spectra. Based on quantum-mechanically modeled spectra, we demonstrate and analyze the accurate imaging of the IR-streaking-pulse-induced transient plasmonic fields at the surface of gold nanospheres and nanoshells with subfemtosecond temporal and subnanometer spatial resolution.

Streaked photoemission from nanostructured surfaces and nanoparticles by attosecond extreme ultraviolet pulses into an infrared (IR) or visible streaking pulse allows for sub-fs-resolution of the plasmonically enhanced streaking-pulse electric field. It thus holds promise for the time-resolved imaging of the dielectric response in and plasmonic fields near nanostructures. After calculating the plasmonic field induced by IR and visible streaking pulses in 10-to 200-nm diameter Au, Ag, and Cu nanospheres, we numerically simulated streaked photoelectron spectra within a quantum-mechanical model. Our spectra show significant oscillation-amplitude enhancements and phase shifts relative to calculations that neglect the induced plasmonic field. We trace these observable effects to the distinct dielectric properties of the three investigated metals, demonstrating the applicability of streaking spectroscopy to the element-specific investigation of induced time-dependent electric fields near nanoparticle surfaces.

In this study, we first investigated changes seen in electrical and optical properties of a polymer light-emitting diode due to using different kinds of solvents and their mixture. Two-layer light emitting diodes with organic small molecules doped in a PVK polymer host were fabricated using (i) non-aromatic solvent chloroform with a high evaporation rate; (ii) aromatic solvent chlorobenzene with a low evaporation rate, and (iii) their mixture with different relative ratios. The effect of nano-scale layer thickness, surface roughness and internal nano-morphology on threshold voltage and the amount of electric current, the luminance and efficiency of a device were assessed. Results indicated the importance of majority charge carriers’ type in the selection of solvent and tuning its properties. Then, the effect of thermal annealing on electrical and optical properties of polymer light emitting diodes was investigated. During the device fabrication, pre-annealing in 80 and/or 120 °C and post-annealing in 120 °C were performed. The nano-scale effect of annealing on polymer-metal interface and electric current injection was described thoroughly. A comparison between threshold voltage, luminance and electric current efficiency of luminescence for different annealing processes was undertaken, so that the best electric current efficiency of luminescence achieved at 120 °C pre-annealing accompanied with 120 °C post-annealing.