Drift mobility of doped a-Si:H at high temperatures

The traveling-wave drift mobility μ was measured in two phosphorus-doped hydrogenated amorphous silicon (a-Si:H) samples which showed at $T_K$≊380 K an upward kink in their conductivity curves and below $T_K$ a metastable excess conductivity after rapid quenching. No abrupt change in μ occurs at $T_K$ indicating that the transport process does not change. The quenched state has a somewhat higher μ indicating less disorder. Above 400 K, μ saturates because deep-lying defect states begin to limit the drift mobility.