The invention belongs to the technical field of
single crystal material preparation, and provides a
barium-
magnesium bimetal boron nitride compound-based
solvent (Ba-Mg DMB), which significantly improves the yield of
hexagonal boron nitride (h-BN) single crystals under high temperature and
high pressure (HPHT) conditions, and further improves the
crystal quality. Compared with the yield of about 12% of a
barium-based
solvent, the yield of the Ba-Mg DMB
solvent is increased by 4.8 times, and the stable yield of about 57.3% is achieved. Researches find that under the HPHT condition, the
magnesium element in Ba-Mg DMB can effectively remove carbon and
oxygen impurities, which plays a key role in promoting the obtaining of h-BN single crystals with excellent quality. The high-quality characteristic is verified through detailed characterization of Raman spectrum, X-
ray diffraction, X-
ray photoelectron
spectroscopy and the like, and is particularly reflected in
photoluminescence and
cathode luminescence characteristics. Through the high carrier mobility shown in the single-layer
graphene, it is directly proved that the h-BN
single crystal derived from Ba-Mg DMB can be used as an ideal packaging material of a two-dimensional device.