Graphite and hexagonal boron nitride(h-BN),despite their structural similarity,exhibit opposing electronic properties,namely,metallic conductivity and wide-bandgap insulation,respectively.In recent years,graphene-h-BN...Graphite and hexagonal boron nitride(h-BN),despite their structural similarity,exhibit opposing electronic properties,namely,metallic conductivity and wide-bandgap insulation,respectively.In recent years,graphene-h-BN heterostructures have attracted significant research interest,with the resulting hybrid B-C-N atomic-layer systems exhibiting distinctive electronic properties.Notably,interface effects play a decisive role in governing the performance of these heterostructures.Nevertheless,owing to the lack of high-quality composites,the interfacial structure in B-C-N materials and the correlation with critical properties such as charge transport and band structure modulation are not fully clear.Here,we report the direct synthesis of a millimeter-sized hexagonal B-C-N composite via a solvent method under high-pressure and high-temperature conditions.Structural characterization reveals that the synthesized B-C-N composite contains isolated graphite and h-BN.Compared with pure h-BN,the B-C-N composite has a narrower bandgap and shows a pronounced photoelectric response in the visible light region.More interestingly,we find a graphite-like B-C compound with a thickness of about 30 nm at the graphite-h-BN interface,which forms Schottky junctions with graphite,thus realizing rectification properties.Our findings provide a method for synthesizing highquality B-C-N composites and offer new insights into the structure of the graphite-h-BN interface.展开更多
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Science Foundation of China(Grant No.U2032215)+1 种基金Jilin Province Major Science and Technology Program,China(Grant No.20240211002GX)the Science and Technology Development Project of Jilin Province(Grant No.SKL202402004).
文摘Graphite and hexagonal boron nitride(h-BN),despite their structural similarity,exhibit opposing electronic properties,namely,metallic conductivity and wide-bandgap insulation,respectively.In recent years,graphene-h-BN heterostructures have attracted significant research interest,with the resulting hybrid B-C-N atomic-layer systems exhibiting distinctive electronic properties.Notably,interface effects play a decisive role in governing the performance of these heterostructures.Nevertheless,owing to the lack of high-quality composites,the interfacial structure in B-C-N materials and the correlation with critical properties such as charge transport and band structure modulation are not fully clear.Here,we report the direct synthesis of a millimeter-sized hexagonal B-C-N composite via a solvent method under high-pressure and high-temperature conditions.Structural characterization reveals that the synthesized B-C-N composite contains isolated graphite and h-BN.Compared with pure h-BN,the B-C-N composite has a narrower bandgap and shows a pronounced photoelectric response in the visible light region.More interestingly,we find a graphite-like B-C compound with a thickness of about 30 nm at the graphite-h-BN interface,which forms Schottky junctions with graphite,thus realizing rectification properties.Our findings provide a method for synthesizing highquality B-C-N composites and offer new insights into the structure of the graphite-h-BN interface.
