International Conference on Solid State Devices and Materials

We report on the high-pressure synthesis of diamond and boron nitride (BN) single crystals and their functional manifestation through impurity control. The synthesis of diamond single-crystals has a long history, and now gem-grade synthetic diamond single-crystals are being mass-produced. Under these circumstances, the control of nitrogen impurity has been newly developed for quantum sensing applications. BN has various industrial applications such as heat-resistant materials, heat insulators, and hard materials, but its properties as a wide-gap semiconductor are also interesting. High-purity hexagonal BN single crystals obtained by the high-pressure synthesis process exhibit high-brightness deep-ultraviolet luminescence behavior and are newly found to be useful as a substrate material for graphene devices. Furthermore, the control of impurities in hBN is of new interest as a next stage in the development of the diamond quantum sensing function described above.