Speaker
Prof.
Juozas Vaitkus
(Vilnius University)
Description
The photoconductivity spectra (PC) and lifetime measurement were used for control of transforms and competition of recombination and generation centres in neutron irradiated MCZ Si. In the as-irradiated material the recombination centres prevail and cause mono-exponential decay with nearly linear decrease of carrier lifetime from several microseconds to sub-nanoseconds with enhancement of fluence from 1012 to 31016 n/cm2. Isochronal 24 hours anneals in the range of temperatures from 80 to 420 C induce variation of the density of different deep levels, which depends on irradiation fluence. Appearance of two-exponential decays and the changes of the effective lifetimes of the initial and asymptotic decays imply the complicated transformations of radiation defects under heat treatments. Qualitatively these transforms can be understood when existence and dominance of cluster defects is assumed. The PC spectra allowed to identity the deep levels playing role in free carrie capture and generation.
Author
Prof.
Juozas Vaitkus
(Vilnius University)
Co-authors
Dr
Ernestas Zasinas
(Vilnius University)
Dr
Eugenijus Gaubas
(Vilnius University)
Prof.
Vaidotas Kazukauskas
(Vilnius University)
Mr
Vidmantas Kalendra
(Vilnius University)
