Transmutation doping is a well established technique for obtaining low doping concentration in silicon.Similarly

in GaAs

this technique can be very useful in order to introduce low doping without compensation.However

these is a lack of data concerning the damage introduced by thermal neutron irradiation and the effect of annealing on the defects appearing during the irradiation.In this work we have studied the defects appearing during the neutron irradiation and the effect of annealing by means of photoluminescence at 77K.The starting samples were (111) oriented GaAs slices doped with Si and grown by the horizontal-zone method. Some parameters of the starting sample are given in the table.