Structural and optical study of GaMnAs/GaAs

摘要

GaMnAs/GaAs was obtained with mass-analyzed low energy dual ion beam depostion technique with Mn ion energy of 1000 eV and a dose of 1.5 × 1018 Mn+/cm2 at the substrate temperature of 400°C and was annealed at 840°C. X-ray diffraction spectra showed that Ga5.2Mn, Ga5Mn8, α-Mn and Mn3Ga were obtained in the as-grown sample. After annealing Mn3Ga and α-Mn disappeared, Ga5Mn8 tended to disappear, Ga5.2Mn crystallized better and new phase of Mn2As was generated. The photoluminescence spectra of the as-grown sample showed that the 1.5042 eV GaAs exciton peak, 1.4875 eV peak involving a carbon acceptor and a broad band near 1.35 eV. After annealing at 840°C, the 1.5042 eV peak and 1.4875 eV shifted to 1.5065 and 1.4894 eV, respectively, and the photoluminescence intensity of the 1.35 eV band increased greatly.