The surface stoichiometry and reconstruction of GaP (001) were investigated by means of reflection high-energy electron diffraction and surface photo-absorption. The experiments were carried out using a solid-source molecular beam epitaxy system with a cracker cell as a P source. When the amount of Ga supplied to the surface was over 2ML, the 2 x 4 reconstruction corresponding to the P-stabilized surface was observed in spite of the existence of excess Ga on the surface. The change of surface reconstruction could be interpreted as follows: the surface was a Ga-terminated structure up to 2ML of Ga supply, then Ga atoms move to some non-periodic sites such as Ga droplets.

Surface Reconstruction of GaP (001) for Various Surface Stoichiometries. M.Yoshikawa, A.Nakamura, T.Nomura, K.Ishikawa: Japanese Journal of Applied Physics, 1996, 35, 1205-8