The diffusivity of H+ was directly determined by means of capacitance transient measurements. The H was released from donor-H complexes, in the space-charge layer of Schottky diodes on n-type material, by the pulsed-laser injection of minority carriers. Capacitance-voltage measurements revealed a recovery of donor dopants after injection. This demonstrated minority-carrier enhanced dissociation of a donor-H complex. Capacitance transients which were recorded during the migration of H+ were analyzed in order to obtain diffusivities at near to room temperature. At 320K, the diffusivity was equal to 10-12cm2/s, to within a factor of 2. An Arrhenius plot of the migration time-constant yielded an activation energy for H+ diffusion of about 0.66eV.

N.M.Johnson, C.Herring, D.Bour: Physical Review B, 1993, 48[24], 18308-11