Free‐carrier lifetime and deep‐level luminescence in semi‐insulating GaAs: The influence of indium doping and growth in a magnetic field

The influence of In doping and/or of growth in a magnetic field on the properties of Czochralski‐grown semi‐insulating GaAs wafers is investigated. We determine the spatial distribution of the free‐carrier lifetime by time‐resolved luminescence in the ps regime. The results are compared with the spatial distribution of the near‐band‐edge and deep‐level luminescence. The macroscopical and microscopical homogeneity of the carrier lifetime and the luminescence intensities are improved by the growth in a magnetic field. Indium doping leads to similar improvements and additionally to an increase of the absolute value of the lifetime. The combination of In doping and growth in a magnetic field gives the best results.