NA INAS(110) INTERFACE FORMATION AT RT

We present a detailed investigation of the Na/InAs(110) interface form ation at room temperature by synchrotron radiation core-level photoemi ssion spectroscopy. At very low Na coverages only one type of adsorpti on site is observed. This stage corresponds to a large downward band b ending for both n- and p-type samples, which leads to a Ferrni-level p inning position well above the conduction band minimum. With further N a deposition a second Na 2p component appears; this is accompanied by a decrease of the band bending. At high coverages one observes a very strong chemical reaction between the substrate and Na. This interface formation is compared with our previous study of the Cs/InAs(110) syst em.