[7a-C19-1~9] 【CS.8】6.5 & 7.6 Code-sharing session

△ [7a-C19-5] Tracing charge transfer dynamics at graphene/SiC interface

〇(DC)Takashi Someya¹, Hirokazu Fukidome², Susumu Yamamoto¹, Norifumi Endo², Takeshi Suzuki¹, Shoya Michimae¹, Mari Watanabe¹, Takashi Yamamoto¹, Masami Fujisawa¹, Teruto Kanai¹, Nobuhisa Ishii¹, Takushi Iimori¹, Fumio Komori¹, Jiro Itatani¹, Kozo Okazaki¹, Shik Shin¹, Iwao Matsuda¹ (1.ISSP, 2.RIEC)

Keywords:graphene, SiC, Photovoltage effect

Graphene, a two-dimensional carbon crystal with a gas of massless Dirac fermions, has promise as a material that is useful in photonic and electronic devices. For these applications, epitaxial growth of graphene by thermal decomposition of a silicon carbide (SiC) is one of the suited fabrication methods as it can directly produce graphene sheet on a semiconducting substrate. However it has been known that graphene/SiC interface have negative effects on electrical properties of graphene, such as carrier mobility, and therefore unrevealing the charge transfer at the interface is essential for the device applications. In this study, we traced the charge transfer dynamics at the graphene/SiC interface by using time-resolved photoemission spectroscopy. For the comprehensive investigation, we utilized two lightsources: laser, for observing electronic population changes in graphene’s Dirac band and synchrotron radiation, for tracing charge transfer dynamics from SiC to graphene. From these combined researches, we will discuss details of the charge transfer dynamics, such as time constants and the effect of interface states on relaxation processes.