Abstract
Positron lifetime measurements have been performed on various semiconductor materials to characterize point defects and vacancy-type imperfections. The technique exploits the enhanced positron trapping at open-volume defects, enabling sensitive detection of vacancy concentrations below parts per million.
Key Results
Distinct lifetime components corresponding to bulk annihilation and defect-trapped positrons were identified. The defect-related lifetimes are consistent with monovacancy and divacancy models, with concentration estimates derived from two-state trapping analysis.
$$ \tau_{\text{eff}} = \frac{1}{\lambda_b + \mu} $$