--- Prospective Students --- (Japanese)
Toward optical communication networks and optical information processing and storage in the 21st century, we are investigating novel high-performance diode lasers and light-controlling devices based on compound semiconductors (optical switches, wavelength converters, optical amplifiers, etc.) as well as highly functional semiconductor integrated devices and circuits fabricated by integrating these discrete devices. For solving energy-related problems, a new class of highly efficient solar cells based on compound semiconductors is also studied. This laboratory serves as a core of the presidential endowed chair of “Global Solar Plus Initiative” since 2010. Crystal growth and processing technologies of quantum micro heterostructures by InGaAsP and InGaAlAs alloys on InP and GaAs substrates, and by III-nitrides such as GaN, AlN, and InN, for fabricating those devices are also investigated.
Large scale photonic integrated circuits (pLSI)
The integration scale of photonic integrated circuits is becoming higher and higher with the advance of ultra-high capacity optical fiber communication technologies. In this laboratory, we are investigating world largest scale photonic integrated circuits (pLSI) for next generation optical communication and interconnect applications, as well as for new applications including bio-imaging.
Ultra-high efficiency photovoltaic cells
In this laboratory, research and development of compound semiconductor concentrated photovoltaic cells are conducted, which have the highest efficiencies among solar cells of all kinds. More specifically, epitaxy and fabrication of multi-junction solar cells utilizing quantum micro structures, development of efficient optical confinement structures, and design and fabrication of concentration optics and tracking mechanism. By forming a team with companies and other universities, we are competing with the US and Germany for the world record of efficiency. Currently, we are working hard to realize a conversion efficiency beyond 50% in 2020.
Renewable energy system based on sunlight energy
An off-grid self-sustaining energy system based on ultra-high efficiency concentrated solar cells is investigated. Our ultimate goal is to establish a sustainable society fully relying on renewable energies, being independent of fossil fuels and nuclear energy. The main target of R&D here is to develop technologies for injecting energy from sunlight into materials efficiently, as well as to develop energy storage media for different applications. The selection of media (gas, liquid, or solid) depends upon whether it is transported over a long distance or used locally, and also upon its usage (combustion, electrical power generaion, fertilizer, etc.). We pursue a novel energy system with the “systems thinking”.
(Photo taken at 2017 lab welcome party)
