In this study, we optimized the condition for forming a single-crystal (111) Cu substrate by using polycrystalline Cu and an abnormal grain growth method. As a result, a single-crystal (111) Cu surface could be formed through annealing for 2 hours in an H 2 (100 sccm) and Ar (200 sccm) gas atmosphere (pressure 70 Torr) at 1050 °C. The crystallinity of the Cu-surface was confirmed by using X-ray diffraction analysis and electron backscatter diffraction (EBSD) pattern imaging and mapping. In addition, chemical vapor deposited graphene was synthesized before and after the crystallinity control of the substrate, and then transferred onto an SiO 2 (300 nm)/Si substrate to perform a Raman spectral analysis and to evaluate the electrical properties through graphene field effect transistor device fabrication. In particular, the mobility of graphene grown on polycrystalline Cu is μ h = 1228 ( μ e = 1158) cm 2 ·V −1 ·s −1 while the carrier mobility of graphene synthesized on a single-crystal Cu surface is μ h = 3353 ( μ e = 3200) cm 2 ·V −1 ·s −1 , showing an improvement of about 273% (276%). Such a single-crystal substrate can be widely used for the synthesis of high-quality 2-dimensional materials and can be reused after the material has been transferred by using a metal etching-free transfer method.

中文翻译：

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单晶铜基板的异常晶粒生长及其上石墨烯的化学气相沉积

在这项研究中，我们通过使用多晶 Cu 和异常晶粒生长方法优化了形成单晶 (111) Cu 衬底的条件。结果，通过在H 2 (100 sccm)和Ar (200 sccm)气氛(压力70 Torr)中在1050℃退火2小时，可以形成单晶(111)Cu表面。通过使用 X 射线衍射分析和电子背散射衍射 (EBSD) 图案成像和映射来确认 Cu 表面的结晶度。此外，在衬底结晶度控制前后合成化学气相沉积石墨烯，然后转移到SiO 2 (300 nm)/Si衬底上进行拉曼光谱分析并通过石墨烯场效应晶体管评估电性能器件制造。特别是，在多晶Cu上生长的石墨烯的迁移率为μ h = 1228 ( μ e = 1158) cm 2 ·V -1 ·s -1 而在单晶Cu表面上合成的石墨烯的载流子迁移率为μ h = 3353 ( μ e = 3200) cm 2 ·V -1 ·s -1 ，显示出约273%（276%）的改进。这种单晶衬底可广泛用于高质量二维材料的合成，并可在材料通过金属无蚀刻转移方法转移后重复使用。