Multimodal measurement Smart lab

Assistant Professor SHITAOKOSHI Takashi

• E-mail
• TEL：022-752-2404

• researchmap
• Scopus

Themes

Control of Physical Properties in van der Waals Layered Materials Using Ion Intercalation

Keywords

van der Waals Layered Materials, Ion Intercalation, Electronic Properties, Transport Properties

Research Activities

Tuning Electronic Properties by “Charging”

  Lithium-ion batteries widely used in everyday life consist of electrolytes containing lithium ions and layered materials that host them. When a voltage is applied, lithium ions in the electrolyte are inserted into the interlayer spaces of the layered material, a phenomenon known as ion intercalation. As ions are introduced into the interlayer spaces, electrons are concomitantly attracted to the layered material, bringing it into a “charged” state.
  Rather than focusing on the operation of the battery itself, attention to the charged layered material reveals that it resides in a state with a higher electron density than in the pristine material. This situation is essentially equivalent to electron doping in semiconductor engineering. When semiconducting materials are employed as the layered material, controlling the degree of charging enables a transition from a semiconducting state to a metallic state and, in some cases, even to a superconducting state.
  I focus on semiconducting layered materials such as HfNCl, in which atomic layers are weakly bound by van der Waals forces. Using electrochemical techniques inspired by battery technology, I perform ion intercalation and investigate how transport properties and electronic states evolve with varying charge density. In addition, I study self-intercalated crystals, in which atoms are already incorporated into the interlayer spaces during synthesis. By comparing these systems with electrochemically intercalated materials, I aim to elucidate both the commonalities and differences in the mechanisms governing the emergence of physical properties.

Message

By applying battery technology to condensed matter physics, I aim to explore novel electronic states in two-dimensional materials. Precise control of ion and electron densities in layered materials enables the creation of previously unexplored functional materials and provides deeper insight into fundamental physical properties.
I welcome discussions and collaborations with students and researchers who are interested in two-dimensional materials, electrochemistry, and transport phenomena.