nanocrystals have been synthesized by hydrothermal method. The average size of obtained spheroid nanocrystals is about 35 nm. The upconversion luminescence intensity can be strengthened by adjusting alkali ions types and contents. The K
+
ions co-doped MgSc
2
O
4
:Er
3+
/Yb
3+
nanocrystals display the strongest luminescence. As K
+
content increasing
emission intensity can be enhanced gradually due to the large asymmetry of crystal field created by K
+
ions. The spectral properties of K
+
ions co-doped MgSc
2
O
4
:Er
3+
/Yb
3+
nanocrystals are described in detail as a function of Er
3+
and Yb
3+
concentrations. The MgSc
2
O
4
:1%Er
3+
/5%Yb
3+
nanocrystal was optimized for the strongest upconversion luminescence. Then
the upconversion mechanism and energy transfer processes between Yb
3+
ions and Er
3+
ions in K
+
ions co-doped MgSc
2
O
4
:Er
3+
/Yb
3+
nanocrystals were investigated under the 980 nm excitation.
关键词
Keywords
references
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