| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:42 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2014 Meeting
Section: Atomic and Molecular Physics; Astrophysics
Title:
FTIR, Raman and Fluorescence spectroscopic characterization of some rare-earth-doped phosphate glasses as bulk and PLD thin films
Authors:
C. R. IORDANESCU(1), I. D. FERARU(1), M. ELISA(1), M. BERCU(2)
Affiliation:
(1) National Institute of R&D for Optoelectronics INOE 2000, Magurele, Romania
(2) University of Bucharest, Faculty of Physics, Magurele, Romania
E-mail
iorda85@yahoo.com
Keywords:
Phosphate glass, Rare-earth ions, Pulsed Laser Deposition, FTIR spectroscopy, Raman spectroscopy, Fluorescence
Abstract:
The present work deals with aluminophosphate glasses belonging to the Li2O–BaO–Al2O3–La2O3–P2O5 system containing rare earth ions (Eu3+, Sm3+, Tb3+ and Nd3+), prepared by a non-conventional wet route. The influence of the RE ions on the optical properties of the phosphate glasses has been investigated in relation with the structural characteristics of the vitreous matrix.
Nd-doped Li2O-BaO-Al2O3-La2O3-P2O5 thin films were obtained by pulsed laser deposition (PLD) technique on silicon wafers considering their applications mainly in optoelectronic devices. In order to perform a satisfactory reproducibility of the stoichiometry between the thin films and the vitreous target, the deposition parameters were modified appropriately. The oxygen pressure and the substrate temperature were varied during the deposition process to investigate the structural and morphological changes of the as-deposited films.
The optical behavior has been studied by ultra-violet–visible (UV–Vis) spectroscopy, revealing electronic transitions specific for RE ions. RE-doped glasses presented few optical absorption peaks in the UV and Vis domains used as excitation wavelengths to generate fluorescence emission. Structural information via vibration modes was provided by Fourier Transform Infrared (FTIR) absorption spectra in the 400–4000 cm-1 range. Absorption peaks specific for the vitreous phosphate matrix were put in evidence as P-O-P symmetrical and asymmetrical stretching vibration modes, P-O-P bend, PO2- symmetrical and asymmetrical stretching vibration modes, P=O stretching vibration mode as well as P-O-H water absorbance. Raman spectra acquired by 514 nm laser excitation disclosed peaks specific for the phosphate matrix too, proving the role of phosphorous oxide as a vitreous network former. Fluorescence spectroscopy measurements on Eu-, Sm-, Tb- and Nd-doped glasses have been performed by excitation with 395 nm, 400 nm, 377 nm and 580 nm respectively.
|
|
|
|