Search results for "electronics"

Acousto-Plasmonic Hot Spots: Driving Enhanced Raman Scattering in Metallic Nanoparticles

2010

We study theoretically and experimentally the coupling of acoustic vibrations (phonons) and surface plasmons in metallic nano-objects. The modulation of the surface charge density allows for the interpretation of experimental Raman-Brillouin spectra in silver nanorods.

Tunable phonon-cavity coupling in graphene membranes

2016

A major achievement of the past decade has been the realization of macroscopic quantum systems by exploiting the interactions between optical cavities and mechanical resonators. In these systems, phonons are coherently annihilated or created in exchange for photons. Similar phenomena have recently been observed through phonon-cavity coupling - energy exchange between the modes of a single system mediated by intrinsic material nonlinearity. This has so far been demonstrated primarily for bulk crystalline, high-quality-factor (Q > 105) mechanical systems operated at cryogenic temperatures. Here, we propose graphene as an ideal candidate for the study of such nonlinear mechanics. The large …

Highly phosphorescent perfect green emitting iridium(iii) complex for application in OLEDs.

2007

A novel iridium complex, [bis-(2-phenylpyridine)(2-carboxy-4-dimethylaminopyridine)iridium(III)] (N984), was synthesized and characterized using spectroscopic and electrochemical methods; a solution processable OLED device incorporating the N984 complex displays electroluminescence spectra with a narrow bandwidth of 70 nm at half of its intensity, with colour coordinates of x = 0.322; y = 0.529 that are very close to those suggested by the PAL standard for a green emitter. Bolink, Henk, Henk.Bolink@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es ; Garcia Santamaria, Sonsoles Amor, Sonsoles.Garcia@uv.es

Front Cover: Metal‐ and Reagent‐Free Anodic Dehydrogenative Cross‐Coupling of Naphthylamines with Phenols (ChemElectroChem 9/2018)

2018

Photoconductivity and photovoltaic effect in indium selenide

1983

Transport and phototransport properties of crystalline indium monoselenide (InSe) doped with a variety of elements are reported. Measured mobilities, lifetimes, and effective diffusion lengths of photoexcited carriers are used to interpret electrical and photovoltaic properties of several different structures. These include p‐n junctions, bismuth/p‐type InSe, platinum/n‐type InSe, and indium tin oxyde (ITO)/p‐type InSe. External solar efficiencies of the best devices are between 5% and 6%. The influence on the efficiency of the various parameters is evaluated, and ways of improvement are discussed.

Photoconductive properties of Bi2S3nanowires

2015

The photoconductive properties of Bi2S3 nanowires synthesized inside anodized alumina (AAO) membrane have been characterized as a function of illuminating photon energy between the wavelengths of 500 to 900 nm and at constant illumination intensity of 1–4 μW·cm−2. Photoconductivity spectra, photocurrent values, photocurrent onset/decay times of individual Bi2S3 nanowires liberated from the AAO membrane were determined and compared with those of arrays of as-produced Bi2S3 nanowires templated inside pores of AAO membrane. The alumina membrane was found to significantly influence the photoconductive properties of the AAO-hosted Bi2S3 nanowires, when compared to liberated from the AAO membrane…

Self-assembled hierarchical nanostructured perovskites enable highly efficient LEDs via an energy cascade

2018

Metal halide perovskites have established themselves as extraordinary optoelectronic materials, exhibiting promise for applications in large area illumination and displays. However, low luminescence, low efficiencies of the light-emitting diodes (LEDs), and complex preparation methods currently limit further progress towards applications. Here, we report on a new and unique mesoscopic film architecture featuring the self-assembly of 3D formamidinium lead bromide (FAPbBr3) nanocrystals of graded size, coupled with microplatelets of octylammonium lead bromide perovskites that enables an energy cascade, yielding very high-performance light-emitting diodes with emission in the green spectral re…

Si nanocrystals embedded in $SiO_2$: Optical studies in the vacuum ultraviolet range

2011

Photoluminescence excitation and transmission spectra of Si nanocrystals of different diameters embeddedin a SiO2 matrix have been investigated in the broad visible-vacuum ultraviolet spectral range usingsynchrotron radiation. The dependence of the photoluminescence excitation spectra on the nanocrystals sizewas experimentally established. It is shown that the photoluminescence excitation and absorption spectra aresignificantly blueshifted with decreasing Si nanocrystal size. A detailed comparison of photoluminescenceexcitation and absorption spectra with data from theoretical modeling has been done. It is demonstrated thatthe experimentally determined blueshift of the photoluminescence exc…

Mechanisms of Strong Photoluminescence from Si Nanocrystals

2011

Photoluminescence mechanisms (models) are reviewed and experimental data are analyzed based on our model, related to direct radiative transitions from the second conduction sub-band to the first one.

Optical properties of ZnMgO films grown by spray pyrolysis and their application to UV photodetection

2015

This work presents a comprehensive optical characterization of Zn1−xMgxO thin films grown by spray pyrolysis (SP). Absorption measurements show the high potential of this technique to tune the bandgap from 3.30 to 4.11 eV by changing the Mg acetate content in the precursor solution, leading to a change of the Mg-content ranging from 0 up to 35%, as measured by transmission electron microscopy-energy dispersive x-ray spectroscopy. The optical emission of the films obtained by cathodoluminescence and photoluminescence spectroscopy shows a blue shift of the peak position from 3.26 to 3.89 eV with increasing Mg incorporation, with a clear excitonic contribution even at high Mg contents. The lin…