Measurements were made of positron lifetime and Doppler broadening in highly As-doped Si containing thermally generated V-As3 defect complexes (vacancy surrounded by three As atoms). Positron de-trapping from the V-As3 defect complex was observed and the binding energy of a positron to the complex was deduced to be 0.27eV. The results explained why 85% of the thermal vacancies formed in highly As-doped Si at above 700K were invisible to positron measurements at high temperatures.

Positron Trapping Kinetics in Thermally Generated Vacancy Donor Complexes in Highly As-Doped Silicon. K.Kuitunen, K.Saarinen, F.Tuomisto: Physical Review B, 2007, 75[4], 045210