Quenching phenomena during Mott-type hopping conduction at temperatures below 125K were studied in As+-implanted semi-insulating material. The crystallinity of the implanted layer was determined by using Rutherford back-scattering and Raman scattering methods. It was found that the as-implanted layer was amorphous, while the annealed layers remained crystalline, and consisted of a disordered structure with a displaced fraction of about 1021/cm3. In the case of samples which were annealed at 500C, it was suggested that some of the As precipitates were located on Ga sites; thus leading to the disappearance of the A1g Raman active mode of the As clusters. Hopping conduction was photo-quenched when the defect concentration reached about 6 x 1017/cm3; thus indicating the re-growth of AsGa antisite defects to be the major component of EL2.

K.Kuriyama, K.Kazama, T.Kato, S.Yamamoto, Y.Aoki, H.Naramoto: Journal of Applied Physics, 1996, 80[8], 4488-90