A GaP(0 0 1) surface treated by S2Cl2 and P2S5/(NH4)(2)S-x, solutions has been investigated by AES and XPS. The amount of sulfur on the surface treated by the P2S5/(NH4)(2)S-x, solution is more than that by the (NH4)(2)S-x. The sulfur coverage on the S2Cl2- and P2S5/...