Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 2...Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 220 cm  ̄-1mode is attribute to As_1 which is associated, at least in part, with EL2 and EL12 defects.For Sedoped samples, the Raman peaks at 205 and 258 cm ̄-1 may be due to vibrational modes in small clus-ters of arsenic, and the 77 and 185  ̄-1modes are probably associated with disorder-activated first order Ra-man scattering.Irradiated results show that the small clusters of arsenic and disorder state are increased with in-creasing irradiation fluences. Other Raman peaks will also be discussed in this paper.展开更多
The induces defects and especially the EL2 defect in 10 MeV electron irradiated undoped semi-insulating(SI) LEC GaAs samples were investigated by using optical transient current spectroscopy (OTCS)technique.The resul...The induces defects and especially the EL2 defect in 10 MeV electron irradiated undoped semi-insulating(SI) LEC GaAs samples were investigated by using optical transient current spectroscopy (OTCS)technique.The results indicate that the density of EL2 defect of irradiated GaAs decreases and the density of EL6 defect in-creases at lower fluence levels. At higher fluences, we observe an increase in density of the EL2 level, howev-er,the density of the EL6 is decreased. It is suggested that on lower fluences, 10 MeV electron irradiation causes the dissociation of the EL2 defect, and may be used to decrease the main donor level EL2 in SI-GaAs.展开更多
文摘Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 220 cm  ̄-1mode is attribute to As_1 which is associated, at least in part, with EL2 and EL12 defects.For Sedoped samples, the Raman peaks at 205 and 258 cm ̄-1 may be due to vibrational modes in small clus-ters of arsenic, and the 77 and 185  ̄-1modes are probably associated with disorder-activated first order Ra-man scattering.Irradiated results show that the small clusters of arsenic and disorder state are increased with in-creasing irradiation fluences. Other Raman peaks will also be discussed in this paper.
文摘The induces defects and especially the EL2 defect in 10 MeV electron irradiated undoped semi-insulating(SI) LEC GaAs samples were investigated by using optical transient current spectroscopy (OTCS)technique.The results indicate that the density of EL2 defect of irradiated GaAs decreases and the density of EL6 defect in-creases at lower fluence levels. At higher fluences, we observe an increase in density of the EL2 level, howev-er,the density of the EL6 is decreased. It is suggested that on lower fluences, 10 MeV electron irradiation causes the dissociation of the EL2 defect, and may be used to decrease the main donor level EL2 in SI-GaAs.