Details

Autor(en) / Beteiligte

• Xu, D.K.
• Yang, S.H.
• Zhang, Y.L.

Titel

Down-converted luminescence and energy transfer of α-KGd1−xEuxF4 nanophosphors with selective excitation

Ist Teil von

• Journal of luminescence, 2013-11, Vol.143, p.298-303

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A series of KGd1−xEuxF4 (x=1, 5, 10, 15, 20, 40, 60, 80 and 100mol%) nanophosphors were prepared by a simple and reproducible hydrothermal route. The structural and morphological properties of the samples were studied by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM), showing uniform nano-sized particles with cubic phase. The excitation spectra disclosed the intrinsic absorption bands of Eu3+5L6 state at 393nm and of Gd3+6IJ state at 272.4nm. From the downconversion (DC) emission spectra, it was found that the optimal Eu3+ concentration was 20mol% and 15mol% under 393nm and 272.4nm excitation, respectively. The nonradiative energy transfer (ET) mechanism is discussed and it turns out that ET of Eu3+–Eu3+ couple and Gd3+–Eu3+ couple occurs mainly via electric dipole–dipole and electric dipole–quadrupole interactions, respectively. From luminescence decay curves, the lifetimes of KGd1−xEuxF4 nanophosphors are seen to decrease with the increase of Eu3+ concentration. Both the emission spectra and luminescence decay curves show that downconversion ET between Gd3+ and Eu3+ ions is more efficient than that between Eu3+ and Eu3+ ions, thus suggesting potential applications in mercury-free fluorescence lamp and plasma display panel under vacuum ultraviolet (VUV) radiation. •We prepare a series of KGd1−xEuxF4 nanocrystals with a simple hydrothermal route.•Concentration quenching phenomenon is observed under selective excitations.•The energy transfer mechanism with selective excitations is explored.•KGd1−xEuxF4 phosphors show excellent emissions under VUV excitaion.