2D Materials and Devices Beyond Graphene Science and Emerging Technology of 2D Atomic Layered Materials and Devices
Abstract
Atomically thin material such as graphene is known to be extremely susceptible to its environment, including defects and phonons in the substrate on which it is placed as well as gas molecules that surround it. Therefore, it is necessary to develop novel methods capable of quantitatively measuring the dynamics of adsorption and desorption of molecules on graphene and the influence of those phenomena on the electronic state of graphene. In this project, the research team has developed temperature-programmed terahertz (THz) emission microscopy that can map the dynamics of absorption and desorption of absorbed molecules on two-dimensional materials and determine the adsorption energy of the molecules. They obtained the first experimental value of the adsorption energy of locally physisorbed oxygen molecules on graphene and WS2. Moreover, the team has developed novel THz time domain spectroscopy (THz-TDS) with parallel-plate waveguides (PPWG) to study atomically thin materials. They demonstrate that a low carrier density graphene, which induces less than 1 absorption in conventional THz-TDS, exhibits ~30 absorption in our PPWG-based system and the signal to noise ratio is dramatically improved.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 31, 2018
- Accession Number
- AD1054853
Entities
People
- Masayoshi Tonouchi
Organizations
- Osaka University