Luminescence Property of Ce3+/Yb3+ Co-doped Silica Material Prepared by Sol-gel Method

The doped materials of trivalent cerium ions and trivalent ytterbium ions can be used as scintillators to detect ionizing radiation. In this work, we investigated the luminescence property of Ce
³⁺
/Yb
³⁺
co-doped silica materials. Our samples with 0.06 mol % Ce
³⁺
, x mol % Yb
³⁺
( x = 0, 0.03, 0.06, 0.09 and 0.30) co-doped silica were prepared by sol-gel method using tetraethoxysilane, cerium nitrate hexahydrate (Ce(NO
₃
)
₃
.6H
₂
O) and ytterbium nitrate pentahydrate (Yb(NO
₃
)
₃
.5H
₂
O) as precursors. The excitation spectra show that the peak at 327 nm of excitation spectrum monitored at 974 nm of the Yb
³⁺
emission matches well with the peak position monitored at 438 nm of the Ce
³⁺
emission, which indicates that there is energy transfer from Ce
³⁺
to Yb
³⁺
in the luminescence process of Ce
³⁺
Yb
³⁺
co-doped silica samples. The emission spectra show that with the increase of Yb
³⁺
doping concentration, the luminescence intensities of Ce
³⁺
decrease gradually. The luminescence intensities of Yb
³⁺
increase first and then decrease. The optimum doping concentration of Yb
³⁺
is 0.06 mol %, and the mol concentration ratio of Ce
³⁺
to Yb
³⁺
is 1 : 1 in our experiments. According to the decay curve, the Ce
³⁺
/Yb
³⁺
co-doping has no obvious influence on the fluorescence lifetime of Yb
³⁺
ions. Meanwhile, the cathodoluminescence spectra show that the CL intensity of Ce
³⁺
/Yb
³⁺
co-doped silica is significantly higher than that of Yb
³⁺
-doped silica. The results show that Ce
³⁺
/Yb
³⁺
co-doped silica materials with broad-band absorption and near-infrared emission have a potential application in radiation detection.