.png){kind=icon}
.png){kind=icon}
Return
Luminescence of BaFBr nanoplates codoped with Eu2+/3+
.png){kind=icon}
PRE
AI
M
P
F
DOI：10.1039/d6dt00603e.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
BaFBr:Eu2+/3+ monodisperse nanocrystals were synthesized via solution-phase thermolysis of metal bromodifluoroacetates. Their luminescence response was characterized between 80 and 430 K. Nanocrystals exhibited square-plate shape with approximate dimensions 33 nm & times; 5 nm and polydispersities below 8% in both dimensions. The emission spectrum of BaFBr:Eu2+/3+ featured a broad band in the near UV arising from fd-f transitions of Eu2+ as well as a series of line-like bands from f-f transitions of Eu3+. No line emission from the 4f(7) (P-6(7/2)) level of Eu2+ was observed. The structure and dynamics of the excited states involved in Eu2+ violet emission were established from the temperature dependence of their time-resolved decays. The lifetime of the 4f(6)5d(1) excited-state manifold exhibited antithermal quenching between 80 and 430 K. This observation could not be rationalized invoking thermalization of the lowest level of the 4f(6)5d(1) manifold to the higher-lying 4f(7) (P-6(7/2)) level. A satisfactory explanation was achieved considering thermal coupling between the lowest level of the 4f(6)5d(1) manifold and a higher-lying 4f(6)5d(1) level. The latter featured a smaller radiative rate than the former (approximate to 10(5)vs. 10(6) s(-1)) and the gap between these two levels was estimated to be approximate to 500 cm(-1). The 4f(7) (P-6(7/2)) level was located approximate to 100 cm(-1) above the higher-lying 4f(6)5d(1) level and, unlike the case of BaFCl, did not need to be invoked at all to rationalize the temperature dependence of Eu2+ emission.
Keywords:
RADIATION-PRODUCED ELECTRON
OXYGEN-CONTAINING BAFBR
PHOTOSTIMULATED LUMINESCENCE
TEMPERATURE-DEPENDENCE
FLUORESCENCE LIFETIME
HOLE-CENTERS
SAMARIUM
CAF2
NANOCRYSTALS
SPECTROSCOPY
Journal
IF:
3.3
Papers:
3.3W
Citations:
7.5W
Organization
Cited Papers