OPTICAL CHARACTERIZATION OF NEUTRON-TRANSMUTATION-DOPED GAAS

Photoluminescence and photoreflectance measurements were carried out i n order to investigate the effects of neutron irradiation induced defe cts in neutron-transmutation-doped (NTD) GaAs. The damages to the crys tallinity of NTD GaAs were recovered by annealing, and the remaining d efects in the annealed NTD GaAs were passivated by hydrogenation. When the transmutation-doped impurities in GaAs were compensated by the in jection of hydrogen atoms, Franz-Keldysh oscillations appeared due to the large variation in the surface electric field.