The influence of antimony (Sb) doping on the luminescent properties of lead tungstate crystals (PWO) has been investigated. Transmission spectra

UV-excited emission spectra and their excitation spectra of PbWO

4

: Sb and undoped PWO before and after annealing in air were reported. the emission spectra of PWO and PWO: Sb before annealing were analyzed by fitting with three Gaussian subbands respectively. Sb doping improved the luminescence of PWO by enormously increasing its light yield.While the green emission band is enhanced

the red one is restrained. On the ground that the improvement by Sb doping is similar to the air annealing effect on PWO luminescence

the mechanism of Sb doping and the origin of the green emission is brief lydiscussed.We suggested that the green emission originate from some local excess oxygen defects

such as (WO

4

2-

+Oi) centers (here Oi means interstitial oxygen atom) because annealing in air increased the green emission significantly. For the mechanism of Sb doping

we supposed that Sb

3+

ions and Sb

5+

ions simultaneously exist in PbWO

4

: Sb crystal. Sb

3+

ions on Pb

2+

sublattice Sb

pb

3+

compensate the local surplus negative charges bringing in by lead vacancies V

pb

resulting from the higher volatility of raw materials PbO than that of WO

3

and so will compete with the creation of oxygen vacancies Vo which have the same charge compensation effect. While the concentration of Vo decrease

the possibility of Oi increase. But after air annealing

the emission intensity of PbWO

4

: Sb is less than that of PWO. This may be due to Sb

5+

on W

6+

sublattice Sb

w

5

which prevent the further increasing of (WO

4

2-

+Oi) centers in PWO: Sb by air annealing.