HIGH-FIELD ELECTRON-TRANSPORT AND HOT-ELECTRON PHENOMENA IN HYDROGENATED AMORPHOUS-SILICON FILMS

Electron transport under high electric held in hydrogenated amorphous silicon (a-Si:H) films has been investigated by means of time-of-light (TOF) measurements. The drift mobility mu increased with increasing a pplied electric field E accompanied by a simultaneous increase in the dispersion parameter alpha resulting in nondispersive transport. The e lectron thermal runaway breakdown held E with optical carrier injecti on decreased with increasing ambient temperature T-a in accordance wit h the hot electron theory in amorphous solids [H. Frohlich: Proc, R. S ec. London A 118 (1947) 521]. The held dependencies of mu and alpha ar e also explained by taking account of the increase in the effective el ectron temperature (hot electron phenomenon) at high field in the theo ry of dispersive transport.