POSITRON-LIFETIME MEASUREMENTS BETWEEN 300-K AND 800-K IN GAAS AND GAP

Positron-lifetime measurements performed at high temperature have been used to investigate vacancy-like defects in various samples of GaAs a nd in GaP. A detailed three-state trapping model, which allows for det rapping, is utilized to show that monovacancylike defects trap positro ns with a binding energy of close to 0.3 eV, while vacancy clusters co nstitute traps deep enough such that no detectable detrapping occurs u p to 800 K.