Theoretical Materials Design for Next-Generation Devices
Our research target is to theoretically reveal the peculiar electronic, magnetic, transport and optical properties in nanoscale materials and atomically thin films such as graphene, transition metal dichalcogenides and other related two-dimensional materials using theoretical and/or computation method. Our new theoretical findings will serve for designing the new functionalities in next-generation electroinic and optical devices which realize the extreme-low-power consumption devices.
Computational Chemistry for Catalysis
We are challenging to “ab initio simulations” for catalytic processes. “Ab initio” is a Latin term meaning that it relies on basic and established laws of nature without additional assumptions or special models. For the purpose, we are trying to 1) develop a new modeling scheme for practical complex surface, and 2) make a large-scale surface reaction model using quantum chemical calculations. We also aim to solve industrial roadblocks using our computational methods; 1) hydrogen production process from various kinds of fuels such as biomass, 2) poisoning and degradation in hydrogen production catalysis or solid oxide fuel cells (SOFCs), and 3) theoretical designing a new catalyst to improve the durability and performance.
Structural Physics using Synchrotron X-rays
Our research target is to investigate the static and dynamical properties of atoms and electrons in energy-momentum space in functional materials using Synchrotron Radiation X-rays for the development of newly functional materials. Currently to elucidate the mechanism of superconductivity discovered with transition metal oxides and Fe-pnictides, and to investigate the origin of catalytic properties of the battery electrodes are focused by inelastic x-ray scattering and x-ray absorption spectroscopy methods.
Process technology in extreme environment
In our laboratory, we are working to develop the high quality graphene samples using the ultrahigh temperature environment technique. We are also developing the fabrication techniques of nano-structures using electron beam nanolithography and next-generation high efficient process technique to utilize the self-organization function in biology. Since the next-generation semiconductor SiC is one of the key materials to realize the low-power consumption society in future, we are also developing the process technology to control the atomic structures on the crystal surfaces.
Our research target is to develop high-performance energy-related materials. Current research topics are development of materials for high-capacity lithium ion batteries and low-power electronics. The former is development of organosulfur polymers as a cathode materials of lithium ion batteries. The latter is development of an amorphous oxide semiconductor of silicon doped In2O3 (In-Si-O) system. Our distinctive approach is utilization of cutting-edge synchrotron radiation analysis.
Energy Storage Nanomaterials Science
Recently, much attention has been focused on development of high-performance rechargeable batteries due to the global energy and environmental crises. Our research interest is to find novel cathode materials toward the next-generation rechargeable battery. In order to realize a high capacity, a stable cycle performance, a rapid charging, and so on, we examine battery performances of various materials such as organic and inorganic compounds, nanomaterials etc., which can take the place of the present general cathode materials, transition metal oxides. We also study operando XAFS to reveal their battery reaction mechanism.
Construction of Functional Materials for Next-Generation Energy Systems
Our group conducts extensive research into functional energy materials ranging from the fundamental science of these materials through to their potential applications. Special emphasis is placed on the study of superconductors and their related materials. We primarily focus on the synthesis of functional superconducting materials for energy generation, storage and usage. An understanding of the emergent phenomena in these materials can lead to the rational design of novel materials with advanced properties. We also advance the science and technology of functional materials for innovative energy grids.
Defect physics in SiC power semiconductor
Present-day Si power electronics suffer from performance limitations due to their material properties. Wide band gap semiconductor silicon carbide (SiC) is a possible solution to this problem. Our current research focuses on defect physics in SiC semiconductor crystals with the aim of improving the crystal quality. We pursue several research topics together with industrial partners. The topics include studies of the following: the formation mechanisms of structural defects in SiC single crystals; the growth surface morphology of SiC crystals; the structural and surface defects in SiC epitaxial films and their influence on electrical properties of SiC power devices.
Growth and Nanoscale Characterization of 2D Materials
We are aiming at applying two-dimensional (2D) materials, like graphene, hexagonal boron nitride, and transition metal dichalcogenides, and their heterostructures to innovative electronics/photonics devices. For this purpose, we are exploring new physics and functions of 2D materials and heterostructures based on their high-quality crystal growth and nanoscale characterization of the structure and physical properties.
Wide band gap semiconductor
According to the IPCC proposal of “450ppm CO2 scenario”, 80% reduction of CO2 emission is required for developing countries as well as the 50% for whole world. These numbers are broken down to the technologies and “End use efficiency” is expected to contribute up to 50%. Thus, the low loss power electronics is most emerging issue amongst all the technologies. Recently, SiC power modules are replacing Si modules in some specified area, because of its low loss feature. Diamond is also known as the extreme candidate for this application, and we are focusing on this next generation material to respond the global requirement.
Research and development on energy and environmental functional materials for a sustainable society
What kind of technology and energy will support the daily life of 100 years after? The vision shows us the way to do research. Tanaka laboratory has developed the new functional nano-materials, such as automotive catalysts, fuel cells and hydrogen recombination catalysts, for sustainable energy in cooperation with the national and international industry, government and academia.
Material Science for Hydrogen Energy Society
Our research target is to develop (i) hydrogen storage materials, which can absorb and desorb hydrogen reversibly at ambient temperature and pressure, for fuel cell applications and (ii) solid-state electrolytes, in which cations such as Li+ and Na+ can diffuse very fast, for rechargeable batteries. We contribute to the realization of a sustainable system through these material developments.