We propose a method to fabricate the chemical p-n junction in wafer-scale epitaxial graphene. In the case of Au intercalation in between graphene and SiC(0001), there exist two structurally distinct phases that result in p-type and n-type doping in the graphene layer, respectively. In the process of in situ Au deposition on our samples, we used a shadow mask to form a sharp junction of different Au coverage. The intercalation of Au atoms induced by thermal annealing leads to the abrupt p-n junction in the graphene layer, which is characterized by angle-resolved photoemission spectroscopy. This p-n junction of graphene is abrupt in the scale comparable to the beam size of approximately 50 μm. This p-n junction of graphene is expected to be atomically abrupt, since there exist only two structurally distinct phases by self-assembly. The proposed method may be useful not only to fabricate a wafer-scale p-n junction of graphene, but also for a fundamental study on atomically abrupt graphene p-n junction.

中文翻译：

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通过金嵌入在 SiC(0001) 上形成石墨烯 pn 结

我们提出了一种在晶圆级外延石墨烯中制造化学 pn 结的方法。在石墨烯和 SiC(0001) 之间插入 Au 的情况下，存在两个结构不同的相，分别导致石墨烯层中的 p 型和 n 型掺杂。在我们的样品上原位 Au 沉积的过程中，我们使用了一个荫罩来形成不同 Au 覆盖率的尖锐结。由热退火引起的 Au 原子的嵌入导致石墨烯层中的突然 pn 结，其特征在于角分辨光电发射光谱。石墨烯的这种 pn 结在与大约 50 μm 的光束尺寸相当的尺度上是突然的。石墨烯的这种 pn 结预计在原子上是突变的，因为通过自组装只存在两个结构不同的阶段。