ANODIC PROCESSES AT NORMAL-TYPE AND PARA-TYPE GAP ELECTRODES

The anodic oxidation of n- and p-GaP in indifferent electrolyte was studied over a wide range of pH and of current densities by current-voltage and analytical methods. Six elementary charges per GaP ″molecule″ were found to be used in the anodic dissolution process under all circumstances studied, a small fraction of which being conduction band electrons. Surface layer formation and passivating effects were observed under certain circumstances. Hole capture by hexacyanoferrate(II) and sulfide ions was found to occur and to lead to the stabilization of the GaP anode. The reactivity of hexacyanoferrate(II) ion towards holes at the GaP electrode is discussed.