“…Such materials are used for the fabrication of a diverse range of optoelectronic devices (solid state lasers, LED's) [1,4,5,6,7] operating in the visible range. The understanding of phosphorus-stabilized GaAs surfaces is of prime importance in both the realization of high quality InGaP/GaAs and AIGaInP/GaAs heterostructures and the modeling of their electronic properties.…”