Photoluminescence of neutron irradiation-induced defects and neutron-transmutation-doping in GaAs was investigated at 10K.The results show that the neutron-transmutation-doping effect can be observed by low temperature photoluminescence.The shift of the C

As

related PL peak is attributed to the increase of donors near conduct band after transmutation-doping.Under the conditions of low transmutation doped concentration the transmutated Ge atoms occupy Ga sites;where as after high fluence irradiation and hence high transmutation-doped concentration obtained some part of the transmutated Ge atoms are placed in As sites.For the irradiation of high neutron fluence 10

17

n/cm

2

and after rapid annealing at 800℃ for 20 seconds

there still exist antisite defects Ga

As

(

E

V+200meV) and complex defects I

Ga

-V

As

but under the neutron irradiation of fluence 10

14

n/cm

2

～10

15

n/cm

2

such defects (mentioned above) have not been found.