Interaction between As and InP(110) studied by photoemission

Arsenic deposition on InP(110) was studied by means of core-level and valen ce-hand photoemission. By systematic spectral decompositions, it was found that the adsorption at room temperature is nonreactive. At elevated tempera tures the As 3d spectra show drastic transformations, indicative of a P-As exchange reaction. The data can at this point be interpreted in terms of a recently proposed structure involving an As-covered InAs layer. Upon As red eposition the core-level spectra are clearly different from those observed prior to annealing, which means that the exchange reaction is irreversible. Angle-resolved valence-band spectra from the reacted surface are similar t o those from clean InP(110), but important differences are found, facilitat ing the identification of surface states.