Abstract:
The modified floating-zone technique involving electric and magnetic fields allows obtaining fairly pure single crystals of undoped GaSb and GaSb doped by Fe. The structure of photoluminescence spectra of undoped GaSb is experimentally identified as radiative transitions of BE1, BE2, BE3, and BE4. In terms of a hydrogen-like model, the activation energy of impurities on which excitons are localized is calculated. The samples GaSb doped by Fe had a p-type of conductivity and it was shown that the Fe in GaSb formed the shallow acceptor level with the ionization energy of 23±2 meV. The concentration of shallow acceptors determined from the Hall measurements is in a good agreement with the concentration of the Fe acceptors obtained from the photoluminescence.