Red phosphor Ca

4

(La

1-x-y

Gd

x

Y

y

)

1-n

O(BO

3

)

3

:nEu

3+

(

Ln

COB:Eu

Ln

= La

1-x-y

Gd

x

Y

y

) was (synthesized) with the method of solid-state reaction at high temperature. The luminescent properties were investigated from vacuum ultraviolet (VUV

E

>

50000 cm

-1

<

200 nm) to visible region. The component with best luminescence intensity was found out and compare with commercial red phosphor. This system shows effective red emission under the excitation of low-pressure mercury lamp. The emission spectra of

Ln

COB:Eu

3+

show the characteristic

5

D

0

7

F

J

(J=0

1

2

3

4) transition of Eu

3+

ions under the excitation of 254 nm. Monitored the strongest

5

D

0

7

F

2

emission line (610 nm)

they all have a broad and strong excitation band which centered at about 246 nm which is ascribed to the charge transfer band (CTB) of Eu

3+

-O

2-

and result in that the phosphor can be excitated efficiently by low-pressure mercury lamp. In the VUV range

there is a broad host absorption band located around 184~188 nm in the range from 150~200 nm

which include the (f-d) transition of Eu

3+

. And for Ca

4

GdO(BO

3

)

3

:Eu

3+

this broad band is very stronger than that in another two hosts

which should be due to the existence of Gd

3+

ions and the excitation efficiency can be enhanced (around) 184~188 nm effectively.