There exists an increasing demand for red emitting phosphors to be used in color display and illumination. SrAl

12

O

19

∶ Eu

2+

has attracted much attention for its excellent properties such as high quantum efficiency and good stability. However

the emission of SrAl

12

O

19

∶ Eu

2+

peaks at 400 nm

which is hard to be used in display and illumination. As we know

Cr

3+

with red emission lines is one of the most used activators for solid state laser and other luminescent materials. Therefore

we have studied the emission and excitation spectra as well as energy transfer in SrAl

12

O

19

∶ Eu

2+

Cr

3+

. The Cr

3+

Eu

2+

singly doped and co-doped samples were synthesized by solid-state reaction at 1 400 ℃. The emission band of Eu

2+

peaked at 400 nm is originating from the 5d-4f transition

which has large spectral overlaps with the

4

A

2

4

T

1

absorption band of Cr

3+

covering between 350 nm and 450 nm in the ultraviolet-blue region. It means the possibility of energy transfer from Eu

2+

to Cr

3+

. The conversion of violet-blue emission to the red may be obtained by the energy transfer. In the co-doped samples

the emission band of Eu

2+

appears in the range of excitation spectra of Cr

3+

emission

which indicates the occurrence of energy transfer from Eu

2+

to Cr

3+

. In order to explain energy transfer further

the lifetime of Eu

2+

emission in SrAl

12

O

19

∶ 1%Eu

2+

x

%Cr

3+

(

x

=0

0.2

1.0

2.0

3.0

4.0

5.0) has been measured. It shows that the lifetime of Eu

2+

reduces following increasing Cr

3+

concentration due to the energy transfer from Eu

2+

to Cr

3+

. The energy transfer efficiency as a function of Cr

3+

concentration has been calculated using the measured fluorescent lifetimes of Eu

2+

indicating the transfer efficiency increases with increasing Cr

3+

concentration

and may reach 50% as Cr

3+

concentration is 0.05.