Cc. Ling et al., Defect study of Zn-doped p-type gallium antimonide using positron lifetimespectroscopy - art. no. 075201, PHYS REV B, 6407(7), 2001, pp. 5201
Defects in p-type Zn-doped liquid-encapsulated Czochralski-grown GaSb were
studied by the positron lifetime technique. The lifetime measurements were
performed on the as-grown sample at temperature varying from 15 K to 297 K.
A positron trapping center having a characteristic lifetime of 317 ps was
identified as the neutral V-Ga-related defect. Its concentration in the as-
grown sample was found to be in the range of 10(17)-10(18) cm(-3). At an an
nealing temperature of 300 degreesC, the V-Ga-related defect began annealin
g out and a new defect capable of trapping positrons was formed. This newly
formed defect, having a lifetime value of 379 ps, is attributed to a vacan
cy-Zn-defect complex. This defect started annealing out at a temperature of
580 degreesC. A positron shallow trap having binding energy and concentrat
ion of 75 meV and 10(18) cm(-3), respectively, was also observed in the as-
grown sample. This shallow trap is attributed to positrons forming hydrogen
like Rydberg states with the ionized dopant acceptor Zn.