5 research outputs found
Photoluminescence of highly doped Cd1-xMnxS nanocrystals
We have synthesized CdS and Cd0 7Mn0 3S nanocrystals with diameters of about 45 nm These materials have been studied using photoluminescence spectroscopy with various excitation energies in the temperature range from 1 8 to 300 K We registered surface and defect states as well as two Mn2+ energy levels that correspond to Mn2+ ions in two different crystal environments. In addition, the resonant behavior of one Mn state excited by 514.5 nm wavelength of laser light has been clearly observed in obtained spectra We proposed the scheme of energy levels and transitions that explain obtained experimental results (C) 2010 Elsevier B V. All rights reserve
Influence of laser-induced heating on MnO nanoparticles
The phase changes of MnO nanoparticles under laser-induced heating have been studied. Previous confirmation of the existence of MnO phase was based on the X-ray diffraction measurements. Here, we report the experimental spectra of nonresonant Raman scattering in the range between 100 and 1,600cm(-1), for a sample irradiated with 8 different laser powers. The laser-induced heating has produced change in existing phases in sample, destruction of MnO phase, and creation of MnO2, Mn3O4, and MnOOH phases along with formation of Mn2+ on the sample surface. These phase changes have been confirmed by X-ray diffraction and atomic force microscopy measurements
Magnetic field influence on optical properties of Cd1-xMnxS (x=0; 0.3) quantum dots: Photoluminescence study
We have synthesized CdS and Cd0.7Mn0.3S nanocrystals with diameters of about 4.5 nm. These materials have been studied using photoluminescence spectroscopy with various excitation energies in the temperature range from 1.8 to 300 K, in magnetic field up to 5T. We registered surface and defect states as well as two Mn2+ energy levels that correspond to Mn2+ ions in two different crystal environments. We proposed the scheme of energy levels and transitions that explain obtained experimental results. (C) 2012 Elsevier B. V. All rights reserved
Surface optical phonon ā Plasmon interaction in nanodimensional CdTe thin films
Structural and optical properties of CdTe thin films were investigated applying atomic force microscopy (AFM), XRD powder technique, Raman spectroscopy and farāinfrared spectroscopy. CdTe thin films were prepared by using thermal evaporation technique. In the analysis of the far ā infrared reflection spectra, numerical model for calculating the reflectivity coefficient for system which includes films and substrate has been applied. Effective permittivity of film mixture (CdTe and air) was modeled by Maxwell ā Garnet approximation. We reveal the existence of surface optical phonon (SOP) mode and coupled plasmon-SOP modes (CPSOPM). Ā© 2018 Elsevier B.V