The temperature dependence of the Shockley-Read-Hall carrier lifetime was studied, in p-i-n diodes that had been irradiated with 15MeV electrons, by using 3 techniques. Flying-spot scanning was used to measure the lifetimes under low-level injection. Open-circuit carrier decay was used to measure high-injection lifetimes, and deep-level transient spectroscopy was used to characterize active recombination centers.. The measurements showed that 2 defect levels, at Ec-0.164eV (E1 - related to the vacancy-oxygen complex) and Ec-0.421eV (E4 - related to the singly negatively charged state of the di-vacancy) were significant with regard to the Shockley-Read-Hall lifetime in various injection domains of the low-doped n-type region. The E1 recombination center predominated with regard to the high-injection lifetime, and the E4 center predominated with regard to the low-injection lifetime. Other defect levels were also observed, but the E1 and E4 levels seemed to be sufficient in order to explain the behavior of electron-irradiated semiconductor power devices.

H.Bleichner, P.Jonsson, N.Keskitalo, E.Nordlander: Journal of Applied Physics, 1996, 79[12], 9142-8