Measurement of positron mobility in Si at 30300 K

The temperature dependence of positron motion in silicon (Si:[P]=4×1014 cm-3) is studied experimentally by measuring the drift length of positrons in the space-charge region of an Au-Si surface-barrier diode. At 300 K the positron mobility is 11015 cm2 V-1 s-1, and it increases to 2800 1000 cm2 V-1 s-1 at 30 K. Below 300 K the mobility varies with temperature in accordance with T-3/2. This temperature dependence of carrier mobility is typical of scattering from longitudinal-acoustic phonons.