GaN as a key material for realizing Internet of Energy
Hiroshi Amano
Center for Integrated Research of Future Electronics (CIRFE), Institute of Materials and Systems forSustainability (IMaSS), Nagoya University, Nagoya, Japan
ABSTRACT

Gallium nitride (GaN) and related compound semiconductors, the so-called group III nitrides,
are thought to be among the most important key materials for next-generation high-power andhigh-frequency devices. In this presentation, by considering a system based on these materials,
I would like to discuss how to establish a sustainable, smart, safe, and secure society throughthe “Internet of Energy” for connecting people at any time and any place. The meaning of thisphrase, “Internet of Energy”, is simple. With the use of a ubiquitous energy transmission
system, we do not need to worry about a shortage of electric power.
One of the most important items for establishing a sustainable society is electric vehicles,
so-called EVs. One of the problems of EVs is their short driving range owing to the insufficient
capacity of the battery. Another is their long charging time. To solve these problems, we aretrying to establish a new wireless electricity transmission system using high-power and highefficiency GaN-based devices. If EVs can be recharged while driving, they will run like trams
but with more freedom as they can be driven anywhere.
In TV programs, images of beautiful scenery taken from flying drones are becoming
increasingly common. Drones have the same problem as EVs, that is, a short range on a single
charge. If drones can be recharged while flying, we can expect them to fly all day, increasing
their applicability to, for example, the inspection of old bridges, roads, and buildings. In Japan,logistics has the problem that the increasing average age of drivers is gradually decreasing thecapacity of logistic systems. If we can apply autonomous drones that can fly 24 hours a day forlogistics, the capacity of logistical systems will be drastically improved. In times ofcatastrophic emergencies, drones can also play a key role in carrying emergency items tovictims.
We will no longer need to worry about electricity shortages not only for EVs and drones, butalso for any electronic system. We can connect electronic systems at any time and any place,thus achieving the “Internet of Energy”.
To realize such a future wireless electricity grid, we should try to seamlessly connect theresearch, development, and commercialization of new systems in which GaN-based highfrequency and high-power devices are to be used. In the case of GaN-based blue LEDs on asapphire substrate, it took 30 years from the first fundamental success to their innovation.
Investors cannot wait 30 years. Innovation should be achieved within 10 years. We are trying
to establish new social infrastructures using GaN-based devices on GaN substrates. In ouruniversity, we have established a new research consortium connecting all the stages fromfundamental science to commercialization. For example, we are now trying to develop killerdefect-free bulk-GaN-substrate growth technology, epitaxial growth technology for verticaland horizontal devices, ion implantation technology, etching technology, and packaging
technology at the Nagoya University campus. Up to now, 47 private companies, 20 universities,

and three national research institutes have joined and are starting to collaborate toward thepractical realization of wireless electricity transmission systems.
We are also starting a new program for graduate students, which is called the DIICollaborative Program. Three different specialists, deployers, innovators, and investigatorsform a team to respond to social crises such as climate change. The Japanese government has
targeted an 80% cut in greenhouse gas emission by 2050 from the current level. To realize thischallenging goal, we need pioneers who can lead research, development, andcommercialization. We believe that our program will foster a large number of future leaders
who will help establishes a sustainable, smart, secure, and safe society.
This work was supported by MEXT “Program for Research and Development of NextGeneration Semiconductor to Realize Energy-Saving Society”, the Ministry of theEnvironment “Project of Technical Innovation to Create a Future Ideal Society and Lifestyle”,
and the Cross-ministerial Strategic Innovation Promotion Program (SIP). This work wascarried out by the members of CIRFE.
BIOGRAPHY

Hiroshi Amano received his BE, ME, and DE degrees in 1983, 1985, and 1989, respectively, from Nagoya
University. From 1988 to 1992, he was a research associate at Nagoya University. In 1992, he moved toMeijo University, where he was an assistant professor, associate professor, and professor from 1998 to 2010.
He moved to Nagoya University, where he was a professor of Graduate School of Engineering from 2011 to2015. On October 1, 2015, he became the director of the Center for Integrated Research of Future Electronics,
Institute of Materials and Systems for Sustainability, Nagoya University. He has also been the director ofthe Akasaki Research Center, Nagoya University since 2011.
He is currently developing technologies for the fabrication of high-efficiency power semiconductors andnew energy-saving devices at Nagoya University. He has 577 publication, and 251 patents. He shared theNobel Prize in Physics 2014 with Professor Isamu Akasaki and Professor Shuji Nakamura "for the inventionof efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources".