HYDROGEN MIGRATION IN A PULSED ELECTRIC-FIELD IN A-SI-H

We have performed hydrogen diffusion experiments in a-Si:H p-i-n diode s subjected to a constant and to a pulsed reverse electric field. Unde r a reverse field, the mean-free-path for diffusion of interstitial hy drogen is enhanced by a factor of at least similar to 4. The results p resented here indicate that the enhancement is not due to the field-dr ift of charged hydrogen atoms, but rather to the reduction in electron ic carrier density under reverse bias. The carriers control the captur e rate of interstitial hydrogen into Si-H traps and, therefore, the li fetime and the mean-free-path for diffusion through interstitials.