The 162^nd Committee on Wide Bandgap Semiconductor Photonic and Electronic Devices organized the 5th Asia-Pacific Workshop on Widegap Semiconductors at Toba Kokusai Hotel (Toba, Japan) during May 22 – 26, 2011.

This workshop focused on the science and technology of wide bandgap semiconductors, including III-nitrides, II-VIs, oxide-based materials, SiC, diamonds, and so forth. This research area has been resulting in the development of optoelectronic and electronic devices, which is now being achieved with significant results. The topical areas include 1. growth and characterization, 2. optoelectronic devices, 3. electronic devices, and 4. environmental, biomedical, and energy applications. The first workshop was held in Hyogo, Japan in 2003, and it was succeeded by the workshops in Taiwan, Korea, and China. The most recent one was the fifth workshop in this report. The workshop statistics are as follows.
Participants: 257 [Japan 157, Overseas 100 (Korea 45, Taiwan 30, China 17, Others 8 (USA, Poland, Singapore, etc.)

Despite the terrible disaster in the eastern part of Japan on March 11, 2011, we attempt to conduct the workshop as scheduled because we believed that it is important to keep the social activity of Japan.

Wide bandgap semiconductors of nitrides (AlGaInN), oxides (ZnO and related materials), SiC, diamonds, and so forth have superior physical properties that include large bandgap energy, high electron saturation velocity, high breakdown voltage, and nontoxicity. These materials are now being investigated for their application to light-emitting diodes (LEDs) and laser diodes (LDs) of ultraviolet to visible wavelength range, and high-power and high-speed electronic devices; some of them are now used practically. Further, these materials are considered as attractive materials for energy-saving and ecological devices. One of the purposes of this workshop was to encourage international partnership of researchers and engineers on these topics of wide bandgap semiconductors, and another purpose was to solve the problems encountered in terms of science and technology. We hope that this workshop contributed to the exchange of noteworthy results and understanding of science and technology among research institutes and companies.

Plenary talks were given by Dr. Kachi (Toyota Central R&D Lab, Japan) “Wide-bandgap semiconductors for vehicle applications,” Prof. Porowski (UNIPRESS, Poland) “History and future prospects of GaN bulk crystal growth,” Prof. S. Keller (Univ. of California, Santa Barbara, USA) “Current status and future directions in GaN electronics,” Prof. Y. M. Yu (Pukyung National Univ., Korea) “The new era of the LED application for the green innovation,” and Dr. T. Nakamura (Sumitomo Electric Ind. Ltd.) “InGaN based green LDs on semipolar {20-21} GaN substrates”. The main topics and statistics of the oral sessions are listed below.

As for the internationality of the workshop, the number of participants from outside Asia had increased from the previous workshops which enabled the top level discussion based on the results obtained in interesting recent studies conducted over the world. The papers that were presented in this workshop have been compiled into an abstract book consisting of 380 pages. These booklets have been dedicated to the chairs of the University-Industry Cooperative Research Committees of JSPS.

The next workshop will be held in Taiwan in 2013. In addition to the four host countries in the first to the fifth workshop, Singapore has been nominated as a new host country. Since more and more practical applications in the field of wide bandgap semiconductors are now being developed, this workshop has a unique raison d’être in terms of the overall understanding of the science and technology of wide bandgap materials.

APWS has been identified as a workshop for discussing electric and photonic devices that use various material systems that can be classified as wide bandgap semiconductors. Despite the disaster in the eastern part of Japan, almost all the scheduled presentations were given. This workshop facilitated fruitful discussions and understandings.

The 162^nd committee extends grateful thanks to JSPS and 23 sponsor companies for financial support, and also expresses sincere thanks to all the committee members for their earnest efforts.