Monolayer epitaxial graphene (EG), grown on the Si face of SiC, is an advantageous material for a variety of electronic and optical applications. EG forms as a single crystal over millimeter-scale areas and consequently, the large scale single crystal can be utilized as a template for growth of other materials. In this work, we present the use of EG as a template to form millimeter-scale amorphous and hexagonal boron nitride (a-BN and h-BN) films. The a-BN is formed with pulsed laser deposition and the h-BN is grown with triethylboron (TEB) and NH3 precursors, making it the first metal organic chemical vapor deposition (MOCVD) process of this growth type performed on epitaxial graphene. A variety of optical and non-optical characterization methods are used to determine the optical absorption and dielectric functions of the EG, a-BN, and h-BN within the energy range of 1 eV to 8.5 eV. Furthermore, we report the first ellipsometric observation of high-energy resonant excitons in EG from the 4H polytype of SiC and an analysis on the interactions within the EG and h-BN heterostructure.

中文翻译：

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测量在外延石墨烯上生长的毫米级非晶和六角形氮化硼薄膜的介电和光学响应。

在SiC的Si面上生长的单层外延石墨烯（EG）是一种适用于各种电子和光学应用的有利材料。EG在毫米级区域上形成为单晶，因此，大型单晶可用作其他材料生长的模板。在这项工作中，我们目前使用EG作为模板来形成毫米级的非晶和六方氮化硼（a-BN和h-BN）膜。用脉冲激光沉积形成a-BN，用三乙基硼（TEB）和NH3前体生长h-BN，这使其成为在外延石墨烯上进行的这种生长类型的第一个金属有机化学气相沉积（MOCVD）工艺。多种光学和非光学表征方法可用于确定EG，a-BN，和h-BN在1 eV至8.5 eV的能量范围内。此外，我们从SiC的4H多型中报告了高能共振激子在EG中的第一个椭圆偏振观测，并分析了EG和h-BN异质结构之间的相互作用。