Defects in p-type Zn-doped liquid-encapsulated Czochralski-grown material were studied by using positron lifetime techniques. Lifetime measurements were performed on as-grown samples at 15 to 297K. A positron trapping center, with a characteristic lifetime of 317ps, was identified as being the neutral VGa-related defect. Its concentration in as-grown samples was found to range from 1017 to 1018/cm3. At an annealing temperature of

300C, the VGa-related defect began to anneal out, and a new defect capable of trapping positrons was formed. This newly formed defect, with a lifetime of 379ps, was attributed to a vacancy-Zn defect complex. This defect began to anneal out at 580C. A shallow positron trap having a binding energy and concentration of 0.075eV and 1018/cm3, respectively, was also observed in as-grown samples. This shallow trap was attributed to positrons which formed H-like Rydberg states with the ionized dopant acceptor, Zn.

Defect Study of Zn-Doped p-Type Gallium Antimonide using Positron Lifetime Spectroscopy. C.C.Ling, S.Fung, C.D.Beling, W.Huimin: Physical Review B, 2001, 64[7], 075201 (7pp)