| Summary: | 碩士 === 國立嘉義大學 === 電子物理學系光電暨固態電子研究所 === 103 === Using high-resolution synchrotron-radiation photoemission, we have studied evolution of the interfacial electronic properties of Ag on a p-GaAs(001)2x4 surface. The photoelectron spectra show that in the initial deposition, Ag is located on top of the As-As dimer in the topmost surface layer. After that, Ag starts to adsorb on the As-As dimer in the third layer. When Ag metal film was formed, the interaction increases with increasing Ag coverage, resulting in the elemental segregation of As and Ga, which diffuse into the Ag film to form As-Ag and Ga-Ag bonds. Diffusion of As and Ga continues at 42.5 Å, where As is found at the Ag surface and Ga in the Ag film. At 5.0 Å the band bending was approximately 0.01 eV, and the Schottky barrier height is determined to be approximately 0.39 eV.
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