In monolayer MoS2, optical transitions across the direct band gap are governed by chiral selection rules, allowing optical valley initialization. In time-resolved photoluminescence (PL) experiments, we find that both the polarization and emission dynamics do not change from 4 to 300 K within our time resolution. We measure a high polarization and show that under pulsed excitation the emission p...

Combining high resolution optical microscopy and spectroscopy, we propose a novel, generally applicable and highly sensitive method for determining the local morphology in organic semiconductor thin films (e.g. perfluoropentacene (PFP)). An azimuthally or radially polarized doughnut mode (APDM or RPDM) laser beam is focused by a high numerical aperture parabolic-mirror to excite a diffraction l...

A low-temperature hydrothermal route has been developed, and pure phase Ba2Ni3F10 nanowires have been successfully prepared under optimized conditions. Under the 325 nm excitation, the Ba2Ni3F10 nanowires exhibit three emission bands with peak positions locating at 360, 530, and 700 nm, respectively. Combined with the first-principles calculations, the photoluminescence property can be explaine...

The ZnO nanoflowers were synthesized by reactive vapor deposition. A secondary nucleation in the stalk/leaves interface was suggested. The photoluminescence revealed that there were many oxygen vacancies in the nanoflowers. To tune the optical properties of ZnO nanoflowers, ZnO thin films with varying thicknesses were coated on the nanoflowers by atomic layer deposition, which can distinctly im...

In this paper we investigate the receipt of cadmium sulfide nanoparticles in the microemulsion system stabilized by nonionic surfactants, and the effect of the volume of microemulsion droplets and supersaturation on the size of the particles formed CdS. The photoluminescence spectrum microemulsion system containing nanoparticles of CdS, is shifted to shorter wavelengths of the spectrum and the ...

zns  nanoparticles  were  synthesized  via  a  simple  surfactant  free microwave  route.  in  this  synthesis, thioacetamide  was  used  as sulfur  source.  the effects  of different  parameters  such  as  type of zinc precursor,  time  and  power  of  irradiation  on  the  morphology and  particle  size  of  the  products  have been  investigated.  the nanostructures  were  characterized  by ...

zno nanorod was prepared by microwave assisted method. the crystal structure of the nano powders were confirmed by x-ray diffraction analysis and the mean particle size was estimated by the scherrer,s formula .the surface morphology of the nano particles were analyzed by   using sem . the absorption spectrum of the material in the uv-vis range was recorded .the energy band gap of the material w...

Near-field photoluminescence spectroscopy was used to study the electronic properties of semiconducting Single-Walled Carbon Nanotubes in different environments. A sharp laser-illuminated metal tip was raster scanned over the sample and served as a strongly confined excitation source. We observed localization of photoluminescence and variations of emission energies along nanotubes on a length s...

calcium fluoride nanoparticles with special amount of cerium ion (%1) were synthesized by coprecipitation. fourier transforms infrared spectroscopy (ftir), x-ray diffraction (xrd), absorption and photoluminescence (pl) from caf2ce nanoparticles has been investigated. ftir spectra reveal that there are some amounts of oh, no3 and other organic functional groups on the particle surfaces before th...

in this article, zno and zno:mn nanoparticles prepared by reverse micelle method. the various crystalline properties of these nanoparticles such as size, d-spacing, strain, stress, dislocation density and texture coefficient have been calculated with the help of xrd spectrum. the xrd results indicated that the synthesized zno and zno:mn nanoparticles have a pure wurtzite (hexagonal phase) struc...