二維材料上的磁性有機半導體異質界面研究

Heterostructures comprised of 2D and magnetic materials, rubrene bilayer structures, and enhancing silicide formation by Ag-Si particles have been investigated under the support from this project. The main scientific outputs of this project are as follows. (1) Intercalation of graphene/Co is fabricated by annealing treatments for Co/graphene/Ir(111) and shows a strong spin-orbital interaction. The magnetic anisotropy energy can be tuned by the introduction of a polarized interface and shows possibly novel applications as spintronics. For Co on graphene/Cu, multiple steps of the hysteresis loop are observed and show applications as spintronic switches. The magnetic response of Co/graphene/Cu can be influenced by the interfacial conditions. (2) We discovered that a rubrene/Si(100) film typically has a cluster-type morphology mainly comprising crystalline nanodomains within the film. As the film thickness is increased, the enhancement in elastic modulus can be attributed to the presence of a soft surface layer on a hard underlayer. We propose a structural bilayer model that can be used to explain the layered nature or characteristics of the rubrene films. Based on four-point probe measurements, the bilayered nature of such materials can be used to characterize their electrical resistive behavior while interfacial roughness is sensitive to the transport paths of conduction electrons. This information is valuable for future applications of organic semiconductors in flexible devices. (3) For Ni/Si(111), the dominant species produced at the interface is NiSi, which is produced by the spontaneous formation of strong bonds between Ni and Si atoms. We established a chemical shift-related concentration model that, in effect, represents a practical method for determining the amount of ultrathin Ni silicides that are produced at the buried interface. The formation of Ag-Si particles provide a viable strategy for enhancing silicide formation via a specific interaction transfer mechanism, even at room temperature. The mechanism is related to differences in the enthalpies of formation for different phases. We have achieved the goal of this project as revealed in the proposal. We have published parts of the results in SCI journals. We appreciate the supports from Ministry of Science and Technology of Taiwan, ROC.