The dissolution ofn-GaAs in 1M KOH has been investigated using neutron activation analysis. For this purposen-GaAs electrodes were irradiated with thermal neutrons. Neutron irradiation induced defects were annihilated by annealing. The corrosion measurements were performed in the plateau region of the photocurrent in 1M KOH with and without Fe(CN)
and at rest potential in the dark (currentless) in the presence of Fe(CN)
. We could prove the hole injection of Fe(CN)
inton-GaAs and the lowering of the photocorrosion due to the presence of Fe(CN)
Forperforming radiochemical photocorrosion measurements, n-GaAs samples were irradiated with thermal neutrons. The resulting changes in charge carrier concentration and mobility are determined by far IR reflectance measurements. A great part of the neutron irradiation induced defects could be annihilated by annealing at temperatures of up to 650°C. The neutron irradiation induced defects are responsible for essential changes in photoelectrochemical characteristics of n-GaAs electrodes in aqueous electrolytes. The photocurrent onset potential is shifted in positive direction and the maximum photocurrent is decreased. After annealing treatment the original photoelectrochemical behavior is restored.
Authors:K. Heckner, G. Majoros, A. Kraft, and R. Landsberg
The lowering of the photocorrosion ofn-GaP in 1M KOH in the presence of several redox systems was investigated using neutron activation analysis. After thermal neutron irradiation of GaP and annihilation of irradiation induced defects by annealing processes the photodissolution was investigated by measuring the activity of the corresponding electrolyte solutions. The dependence of the stabilization of the photoelectrode on concentration and redox potential of the reduced form of the redox couples I–, Fe (CN)
was measured. It was found that the stabilization is growing with growing concentration and lowering of the redox potential of the corresponding redox couple.