Defects in Electron Irradiation Te-Doped GaSb Studied by Positron Lifetime Spectroscopy
Defects induced by electron irradiation in Te-doped liquid-encapsulated Czochralski–grown GaSb were studied by the positron lifetime spectroscopy. The lifetime measurements under room temperature indicated there were VGa-related defects with a characteristic lifetime of 298 ps in the heavily Te-doped as-grown GaSb samples. The average lifetime increased with the increase of irradiation dose in lightly Te-doped GaSb,but the behavior was opposite in the heavily Te-doped samples. It should be due to the shift of Fermi level in heavily Te-doped GaSb and the occurrence of gallium vacancies in different charge states. In the temperature dependence measurements carried out on heavily Te-doped samples, we observed positron shallow trap, and this shallow trap should be attributed to positrons forming hyrogenlike Rydberg states with GaSb antisite defects.
S. J. Wang, Z. Q. Chen, B. Wang and Y. C. Jean
H. Li et al., "Defects in Electron Irradiation Te-Doped GaSb Studied by Positron Lifetime Spectroscopy", Materials Science Forum, Vol. 607, pp. 140-142, 2009