77 J. Electroanal. Chem., 317 (1991) 77-W Elsevier Sequoia S.A., Lausanne JEC 01721 Corrosion of III-V compounds; a comparative study of GaAs and InP II. Reaction scheme and influence of surface properties P. Allongue l and S. Blonkowski UPR 15, Physique des Liquides et Electrochimie, Vniversitk Pierre et Marie Curie, tour 22, 4 place Jussieu, F-75252 Park Ceder 05 (France) (Received 12 April 1991; in revised form 17 June 1991) Abstract The paper presents a detailed reaction model for the corrosion of III-V compounds which quantitatively represents the experimental data (mainly Tafel plots of current vs. band displacement), presented in Part I J. Electroanal. Chem. Such data allow the discrimination between different reaction schemes. From a physical point of view, the model shows clearly that the differences observed between GaAs and InP arise from their different electronic surface properties. From a chemical point of view, a chemical signature of the corrosion states of GaAs is proposed: the states E, - 0.98 eV and E, - 1.15 eV, previously derived from photocapacitance spectroscopy, Ber. Bunsenges. Phys. Chem. 92 (1988) 895, could be associated with As sites and Ga sites, respectively. An analogous description holds for InP, with different positions of states. Within the framework of these original data, corrosion can be described by a first hole capture process on the cation site which becomes an anion site by the liberation of the cation. A chemical reaction step occurs before the second hole capture proceeds to dissolve the anion-related defect. Such a description is predicted by thermodynamical data and is further sustained by experimental facts such as the well-known As enrichment of GaAs surface in acidic media. I. INTRODUCTION The (photo-jcorrosion of III-V compounds has been receiving much attention for several decades, due to the importance of these materials for electronic applications and their excellent properties for solar energy conversion by means of l Present address: Dept. of Physical Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, W-1000 Berlin 33, Germany. 0022-0728/91/$03.50 0 1991 - Elsevier Sequoia S.A. All rights reserved