Effect in GaAs produced by fast neutrons and protons

It has been found that of P-type defects to total defect formation is larger in GaAs samples irradiated with high-energy (65 MeV) protons or fast neutrons. The E4 and E5 defects are annealed out after heat treatment of such samples at a temperature near 200°C; as a result, the shape and intensity of the U band change somewhat.