| Summary: | 碩士 === 國立清華大學 === 物理學系 === 99 === We have studied interfacial behavior of CuPc on Ag thin films/Ge(111) and Ag thin films/Au(111) by angle-resolved photoemission spectroscopy (APRES). To preparing a well-ordered Ag thin film, we deposited Ag at about 130 K and then annealed it to room temperature. After obtaining a uniform Ag thin film, we started to evaporate CuPc on Ag film and perform APRES measurement at room temperature. Although CuPc is all deposited on the Ag thin films, the interfacial electronic structure between CuPc and Ag film changes when substrate is different. For CuPc on Ag thin film/Au(111), the electronic structure of CuPc is similar to CuPc on Ag(111), while for CuPc/Ag films/Ge(111), gap state appears at the band edge of the gap which is caused by the interaction between Ag QWS and Ge heavy hole band edge, so the gap state position will change with the thickness of Ag thin film. With the presence of gap state to pin the Fermi level, the HOMO position of CuPc changes with the thickness of Ag thin film. From these evidences, we can conclude that, although CuPc is deposited on the same Ag thin film, the interfacial electronic structures between CuPc and Ag can be different due to the influence from the substrate below the Ag thin film.
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