Symposium X—MRS/The Kavli Foundation Frontiers of Materials

Monday, November 27
12:15 pm – 1:15 pm
Sheraton, 2nd Floor, Grand Ballroom

takashi-taniguchi
Takashi Taniguchi
National Institute for Materials Science

Takashi Taniguchi received his PhD degree in 1987 at the Tokyo Institute of Technology (TIT). After working as a research associate at TIT, he moved to the National Institute for Research in Inorganic Materials (NIRIM) in 1989. After NIRIM unified to the National Institute for Materials Science (NIMS) in 2001, he worked as a group leader of the high-pressure group. He was promoted as a Fellow in 2018 and as an executive vice president of NIMS in 2023. His research activity concerns materials science under high pressure, especially for diamond and boron nitride. Taniguchi was a former president of The Japan Society of High Pressure Science and Technology (JSHPST). His honors include a Commendation for Science and Technology by MEXT Japan (2017), JSHPST Award, (2018), Citation Laureate for 2022 by Clarivate, the Ichimura Prize in Science for Distinguished Achievement (2022), and the James C. McGroddy Prize for New Materials (American Physical Society) (2023).

Hexagonal Boron Nitride Crystal Growth and Applications

Hexagonal boron nitride BN (hBN) and cubic BN (cBN) are known as the representative crystal structures of BN. The former is chemically and thermally stable, and has been widely used as an electrical insulator and heat-resistant material. The latter, which is a high-density phase, is an ultrahard material second only to diamond. Among those BN crystals, some progress in the synthesis of high purity BN crystals was achieved by using Ba-BN as a growth solvent material at high pressure (HP) of 5.5 GPa. Band-edge natures (cBN Eg=6.2eV and hBN Eg=6.4eV) were characterized by their optical properties. The key issue to obtain high purity crystals is to reduce oxygen and carbon contamination in HP growth circumstances. Then, an attractive potential of hBN as a deep ultraviolet (DUV) light emitter and also superior properties as a substrate of 2-dimensional (2D) atomic layer devices such as graphene were realized. In recent years, h-BN has been applied not only as a 2D substrate material, but also as a low-loss dielectric, an infrared confinement device (phonon polariton), and a host material for quantum sensing such as post NV-diamond.

Also, controlling of boron and nitrogen isotope ratio (¹⁰B,¹¹B and ¹⁵N) in hBN and cBN crystals can now be carried out by metatheses reaction under HPHT.

In this paper, our recent studies on hBN single crystal growth under HP with respect to impurity controls for exploring new functions will be reported.

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