Premium
Optical Spectroscopy and Excited‐State Dynamics of Eu 3+ ‐Doped Bismuth Borate Glasses Containing CuO
Author(s) -
Jiménez José A.,
Darley Brien
Publication year - 2020
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.202000396
Subject(s) - photoluminescence , analytical chemistry (journal) , spectroscopy , boron , luminescence , amorphous solid , bismuth , absorption spectroscopy , quenching (fluorescence) , materials science , excited state , emission spectrum , band gap , fourier transform infrared spectroscopy , borate glass , absorption (acoustics) , doping , chemistry , spectral line , crystallography , fluorescence , optics , atomic physics , physics , optoelectronics , organic chemistry , chromatography , quantum mechanics , astronomy , metallurgy , composite material
Bismuth borate glasses containing phosphors and luminescent rare‐earths are of interest for applications in light‐emitting devices. Herein, the influence of CuO impurities on red‐emitting Eu 3+ ‐doped bismuth borate glasses of the 25Bi 2 O 3 ‐15BaO‐10Li 2 O‐50B 2 O 3 type was investigated by various spectroscopic methods. The glasses were prepared by the melt‐quench technique and characterized by X‐ray diffraction (XRD), Fourier transform‐infrared (FT‐IR) spectroscopy, UV/Vis optical absorption (OA), and photoluminescence (PL) spectroscopy including decay kinetics assessment. The XRD data confirmed the amorphous nature of the glasses whereas FT‐IR spectra indicated the basic structural features of trigonal BO 3 units and BO 4 tetrahedra. The OA analysis showed that addition of CuO up to 0.5 mol% results in significant growth of the visible Cu 2+ absorption band around 715 nm, with slight decrease in the optical band gap energies assessed through Tauc plots. A drastic PL quenching of Eu 3+ ions emission was evidenced concurring with the detrimental effect of Cu 2+ . The assessment of the Eu 3+ emission decay curves revealed significant lifetime decrease of the 5 D 0 emitting state with increasing CuO concentration. An analysis of quenching constants was finally performed comparing results from integrated PL data with the emission decay rates. It is argued that the bismuth borate glass system supports an effective Eu 3+ →Cu 2+ energy transfer (more so than phosphates) in connection with a strong spectral overlap between Eu 3+ emission and Cu 2+ absorption.