Determination of Short-Range Motion of Hydrogen in Amorphous Silicon Multilayers by Low-Angle Neutron Scattering

Abstract

The diffusion coefficient of hydrogen in amorphous silicon deposited at 77 K has been measured by monitoring the decay of the low-angle neutron scattering intensity during annealing of Si:H/Si:D/Si:H/Si:D/... multilayers. Diffusion coefficient values ranging from 1 · 10-19 cm2/s to 5 · 10-19 cm2/s have been obtained for annealing temperatures between 250 °C and 300 °C. These very low values confirm recent experiments of Shinar et al. and show that the motion of hydrogen atoms may be impeded by microstructures in amorphous silicon.