Localized Vibrational Mode in Manganese-Doped Zinc Sulphide and Cadmium Sulphide Nanoparticles

Defect modes in ZnS:Mn and CdS:Mn nanoparticles are investigated by means of Fourier transform infrared spectroscopy and the Raman technique for local vibrational modes (LVM), and the observed modes are explained theoretically by using a molecular model.

Electroluminescence Devices with CdS and CdS:Mn Nanoparticles and Polymer Blends

ABSTRACTWe have investigated the photophysical properties of surface capped CdS and CdS:Mn nanoparticles in the form of spin coated thin films of the pure nanoparticles and nanoparticle -polymer blends. The organic capping reagent was p-thiocresol. Electroluminescence (EL) devices were fabricated and characterized by their current/voltage characteristics and EL emission performance. This is to our knowledge the first report on Mn doped CdS nanoparticles applied in EL devices with a single layer device structure (ITO/CdS:Mn/Al). Photoluminescence (PL) and PL excitation measurements were performed on CdS:Mn nanoparticles in pyridine dispersion and on thin films. The PL excitation spectrum shows a narrow peak at 390nm. Excitation at this wavelength yields a broad PL spectrum spanning from about 450 to 700nm, which is dominated by a strong emission band at 585nm. This emission is attributed to transitions involving Mn levels in previous works. The EL emission peak is shifted to the red compared to the PL emission spectra. The characteristics and performance of these new types of EL devices will be presented and discussed.