M. Elisa, C Vasiliu, A. Meghea, N. Iftimie, M. Giurginca, H. J.Trodahl, M.Dalley, CdSSe-doped aluminophosphate glasses obtained by a wet method, Physics and Chemistry of Glasses, 46/6 (2005) 499-504

Title: CdSSe-doped aluminophosphate glasses obtained by a wet method

Abstract: Aluminophosphate glasses doped with CdSxSe1-x, have been produced by a wet nonconventional method that provides a better homogeneity of the glass matrix. The glass samples belong to the oxide systems: Li2O-BaO-Al2O3 La2O3-SiO2-P2O5 and Li2O-Na2O-BaO-Al2O3-La2O3-SiO2-P2O5. The land gaps of the doped samples were determined by UV-VIS-NIR transmission spectroscopy, using the dependence of the absorption coefficient on photon energy. Structural investigations on semiconductor doped glasses were performed by infrared absorption and Raman spectroscopy. Infrared absorption spectra revealed structural units of the phosphate glass matrix. Raman spectra obtained by excitation with 458 and 514 nm revealed CdS0.696Se0.304 peaks and by excitation with 325 nm, revealed the phosphate matrix bonds. Transmission electron microscopy, selected area electron diffraction (SAED) and fluorescence spectroscopy were used to investigate the semiconductor doped glasses. SAED patterns allowed the calculation of the composition and consequently the band gap of the CdSSe crystallites embedded in the glass matrix. A strong CdSSe fluorescence was observed, indicating well ordered crystallites with a molar fraction of S and Se close to 0.5 as intended.

Key words: Quantum Dots; Optical-Properties; Wave-Guides; Absorption; Matrix; Films