Presentation Information
[2I08]Dielectric properties of hydrogen-terminated C(111) thin films
*Hayato Kobayashi1, Akira Sumiyoshi1, Ranferi Cancino Betancourt1, Shota Sato1, Jun Nakamura1 (1. Graduate School of Informatics and Engineering, The University of Electro-Communications)
Unlike previous reports on the a decreased dielectric constant near the surface of Si(111)-H thin films, the present study reveals an opposite trend for C(111)-H thin films, where the dielectric constant is enhanced. Both materials possess a surface-localized nearly free electron (NFE) state, however, their contrasting dielectric behaviors are attributed to the differing energetic position of this state. In C(111)-H thin films, the NFE state constitutes the conduction band minimum (CBM), making it the primary contributor to the dielectric response. In contrast, in Si(111)-H thin films, the NFE state is located at a higher energy level, apart from the CBM, and is thus not significantly influential in the dielectric properties. Therefore, it is concluded that the energetic alignment of surface-localized states relative to the band edges is the decisive factor governing the local dielectric constant in these isostructural systems.