YVO

4

: Eu

3+

was successfully synthesized by hydrothermal method

and was further thermally treated at 400~800 ℃

respectively. Their crystal structure

SEM(scanning electron microscope)images and luminescence properties were obtained in room temperature. XRD showed that YVO

4

: Eu

3+

was formed with good single phase

and when the temperature changes in 400~800 ℃

the crystallinity is higher and higher

and the crystal grain become bigger and bigger than untreated sample. SEM images also indicated the grain of the sample after treatment is bigger than that of YVO

4

: Eu

3+

before treatment. In the UV range

the excitation band is composed of a broad band with the maximum at about 260 nm and a sharp band with the maximum at about 395 nm. The peak of 260 nm is assigned to the overlap of VO

3-

4

ion and O

2-

→Eu

3+

charge transfer band absorption; the peak at 395 nm is due to

7

F

0

→

5

L

6

transition of Eu

3+

. In the VUV range

the excitation band was composed of a strong broad band at about 156 nm and a broad band at about 200 nm. The peak of 156 nm could be assigned to the absorption band of host

and the peak of 200 nm is assigned to the charge transfer band of O

2-

→Y

3+

. After 200 nm

the shape of absorption spetrum is similar to the UV excitation spectra. under 254 nm excitation

the YVO

4

∶ Eu

3+

phosphor exhibits the well-known Eu

3+

emission

which makes up of several sharp lines of Eu

3+

namely the

5

D

0

→

7

F

1

5

D

0

→

7

F

2

5

D

0

→

7

F

4

transitions

respectively

the dominated emission peak is

5

D

0

→

7

F

2

at 619 nm under 147 nm excitation

their emission spectra are consistent with that under 254 nm excitation. With the temperature increasing in 400~800 ℃

the emission intensity of samples is improved because of the higher crystallinity

bigger grain

and removing of OH

-

and VO

3-

4

which can quench the luminescence. Under 254 nm and 147 nm excitation

the emission intensity of the sample thermally treated at 800 ℃ is improved 90% and 95% comparing with the untreated sample

respectively. It was indicated that 800 ℃ is the best thermal treatment temperature.