Kinetics of defect creation by pulsed laser illumination in hydrogenated amorphous silicon films deposited from pure silane and from silane-helium mixtures

The pulsed laser-soaking technique was employed to study the kinetics of defect creation in two types of samples. The laser pulse energy density U was varied in the range (2.5 - 33) 10^-3 J cm^-2. After a rise time nearly independent of U, a steady-state defect density N_SS is observed which varies linearly with U. A model including light-induced annealing of defects fits the present data. N_SS as well as the light-induced creation and light-induced annealing terms are found to be higher in standard samples than in He-diluted samples and confirm the better stability of the latter.