Liu Lixin, Zhou Hailong, Cheng Rui, Chen Yu, Lin Yung-Chen, Qu Yongquan, Bai Jingwei, Ivanov Ivan A, Liu Gang, Huang Yu, Duan Xiangfeng
Department of Chemistry and Biochemistry, University of California, Los Angeles, California, 90095, USA ; Department of Materials Science and Engineering, University of California, Los Angeles, California, 90095, USA.
Department of Chemistry and Biochemistry, University of California, Los Angeles, California, 90095, USA.
J Mater Chem. 2012 Jan 28;22(4):1498-1503. doi: 10.1039/C1JM14272K.
Graphene has attracted considerable interest as a potential material for future electronics. Although mechanical peel is known to produce high quality graphene flakes, practical applications require continuous graphene layers over a large area. The catalyst-assisted chemical vapor deposition (CVD) is a promising synthetic method to deliver wafer-sized graphene. Here we present a systematic study on the nucleation and growth of crystallized graphene domains in an atmospheric pressure chemical vapor deposition (APCVD) process. Parametric studies show that the mean size of the graphene domains increases with increasing growth temperature and CH partial pressure, while the density of domains decreases with increasing growth temperature and is independent of the CH partial pressure. Our studies show that nucleation of graphene domains on copper substrate is highly dependent on the initial annealing temperature. A two-step synthetic process with higher initial annealing temperature but lower growth temperature is developed to reduce domain density and achieve high quality full-surface coverage of monolayer graphene films. Electrical transport measurements demonstrate that the resulting graphene exhibits a high carrier mobility of up to 3000 cm V s at room temperature.
石墨烯作为未来电子学的潜在材料已引起了广泛关注。尽管已知机械剥离可产生高质量的石墨烯薄片，但实际应用需要大面积的连续石墨烯层。催化剂辅助化学气相沉积（CVD）是一种有前景的合成方法，可用于制备晶圆尺寸的石墨烯。在此，我们对大气压化学气相沉积（APCVD）过程中结晶石墨烯域的成核和生长进行了系统研究。参数研究表明，石墨烯域的平均尺寸随生长温度和CH分压的增加而增大，而域的密度随生长温度的升高而降低，且与CH分压无关。我们的研究表明，铜衬底上石墨烯域的成核高度依赖于初始退火温度。开发了一种两步合成工艺，该工艺具有较高的初始退火温度但较低的生长温度，以降低域密度并实现高质量的单层石墨烯膜全表面覆盖。电输运测量表明，所得石墨烯在室温下表现出高达3000 cm² V⁻¹ s⁻¹的高载流子迁移率。
