Growth of Large Single-Crystalline Two-Dimensional Boron Nitride Hexagons on Electropolished Copper
Growth of Large Single-Crystalline Two-Dimensional Boron Nitride Hexagons on Electropolished Copper
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DOI：
10.1021/nl404207f
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发表时间：
2014-02-01
期刊：
影响因子：
10.8
通讯作者：
Karna, Shashi P.
中科院分区：
文献类型：
--
作者：
Tay, Roland Yingjie;Griep, Mark H.;Karna, Shashi P.
受阻氮化硼（h-BN）或“白色石墨烯”具有许多突出的性质，包括高热导率、高机械强度、化学惰性和高电阻，这开辟了广泛的应用，例如热界面材料、保护涂层和纳米电子学中的电介质，其容易超过与基于石墨烯的应用有关的当前广告益处。迄今为止，使用化学气相沉积（CVD）的h-BN膜的开发已经导致在不同金属表面上成核三角形或不对称金刚石形状。此外，三角形畴的平均尺寸保持相对较小（类似于0.5 μ m（2）），导致大量的晶界和缺陷。虽然CVD生长的石墨烯的Cu表面的形态可能对成核密度、域尺寸、厚度和均匀性有影响，但是Cu表面的粗糙度降低对形成h-BN膜的影响是未知的。在这里，我们报告了在常压CVD条件下使用高度电抛光的Cu衬底的新型大面积h-BN六边形的生长和表征。我们发现，h-BN的成核密度显着降低，而域尺寸增加。在这项研究中，观察到的最大六边形h-BN域为35 μ m（2），这是一个数量级大于一个典型的三角形域。当畴聚结以形成连续膜时，较大的晶粒尺寸提供更原始和更光滑的膜，具有更少的晶界诱导的缺陷。
Hexagonal-boron nitride (h-BN) or "white graphene" has many outstanding properties including high thermal conductivity, high mechanical strength, chemical inertness, and high electrical resistance, which open up a wide range of applications such as thermal interface material, protective coatings, and dielectric in nanoelectronics that easily exceed the current advertised benefits pertaining to the graphene-based applications. The development of h-BN films using chemical vapor deposition (CVD) has thus far led into nucleation of triangular or asymmetric diamond shapes on different metallic surfaces. Additionally, the average size of the triangular domains has remained relatively small (similar to 0.5 mu m(2)) leading to a large number of grain boundaries and defects. While the morphology of Cu surfaces for CVD-grown graphene may have impacts on the nucleation density, domain sizes, thickness, and uniformity, the effects of the decreased roughness of Cu surface to develop h-BN films are unknown. Here, we report the growth and characterization of novel large area h-BN hexagons using highly electropolished Cu substrate under atmospheric pressure CVD conditions. We found that the nucleation density of h-BN is significantly reduced while domain sizes increase. In this study, the largest hexagonal-shape h-BN domain observed is 35 mu m(2), which is an order of magnitude larger than a typical triangular domain. As the domains coalesce to form a continuous film, the larger grain size offers a more pristine and smoother film with lesser grain boundaries induced defects.