Hexagonal boron nitride (h-BN) has attracted significant attention because of its superior properties as well as its potential as an ideal dielectric layer for graphene-based devices. The h-BN films obtained via chemical vapour deposition in earlier reports are always polycrystalline with small grains because of high nucleation density on substrates. Here we report the successful synthesis of large single-crystal h-BN grains on rational designed Cu-Ni alloy foils. It is found that the nucleation density can be greatly reduced to 60 per mm(2) by optimizing Ni ratio in substrates. The strategy enables the growth of single-crystal h-BN grains up to 7,500 mu m(2), approximately two orders larger than that in previous reports. This work not only provides valuable information for understanding h-BN nucleation and growth mechanisms, but also gives an effective alternative to exfoliated h-BN as a high-quality dielectric layer for large-scale nanoelectronic applications.
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机译:六方氮化硼(h-BN)由于其优越的性能以及作为基于石墨烯的器件的理想介电层的潜力而备受关注。在较早的报道中,通过化学气相沉积获得的h-BN膜始终是具有小晶粒的多晶,因为在基底上的成核密度很高。在这里,我们报告了在合理设计的Cu-Ni合金箔上成功合成了大型单晶h-BN晶粒。通过优化基板中的镍比例,可以发现成核密度可以大大降低到60 mm / mm(2)。该策略可以使单晶h-BN晶粒生长到7500μm(2),比以前的报告大两个数量级。这项工作不仅为理解h-BN的成核和生长机理提供了有价值的信息,而且为剥离的h-BN作为大规模纳米电子应用的高质量介电层提供了有效的替代方法。
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