Belotcerkovtceva Daria, Nameirakpam Henry, Datt Gopal, Noumbe Ulrich, Kamalakar M Venkata
Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-751 20, Sweden.
Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504, 23 rue du Loess, Strasbourg 67034, France.
Nanoscale Horiz. 2024 Feb 26;9(3):456-464. doi: 10.1039/d3nh00338h.
Achieving enhanced and stable electrical quality of scalable graphene is crucial for practical graphene device applications. Accordingly, encapsulation has emerged as an approach for improving electrical transport in graphene. In this study, we demonstrate high-current treatment of graphene passivated by AlO nanofilms as a new means to enhance the electrical quality of graphene for its scalable utilization. Our experiments and electrical measurements on large-scale chemical vapor-deposited (CVD) graphene devices reveal that high-current treatment causes persistent and irreversible de-trapping density in both bare graphene and graphene covered by AlO. Strikingly, despite possible interfacial defects in graphene covered with AlO, the high-current treatment enhances its carrier mobility by up to 200% in contrast to bare graphene samples, where mobility decreases. Spatially resolved Raman spectroscopy mapping confirms that surface passivation by AlO, followed by the current treatment, reduces the number of sp defects in graphene. These results suggest that for current treated-passivated graphene (CTPG), the high-current treatment considerably reduces charged impurity and trapped charge densities, thereby reducing Coulomb scattering while mitigating any electromigration of carbon atoms. Our study unveils CTPG as an innovative system for practical utilization in graphene nanoelectronic and spintronic integrated circuits.
实现可扩展石墨烯增强且稳定的电学质量对于石墨烯器件的实际应用至关重要。因此，封装已成为一种改善石墨烯中电传输的方法。在本研究中，我们展示了对由AlO纳米薄膜钝化的石墨烯进行高电流处理，作为一种提高石墨烯电学质量以实现其可扩展利用的新手段。我们对大规模化学气相沉积（CVD）石墨烯器件进行的实验和电学测量表明，高电流处理会在裸石墨烯和被AlO覆盖的石墨烯中导致持续且不可逆的去俘获密度。引人注目的是，尽管被AlO覆盖的石墨烯可能存在界面缺陷，但与裸石墨烯样品中迁移率降低相反，高电流处理使其载流子迁移率提高了高达200%。空间分辨拉曼光谱映射证实，AlO进行表面钝化后再进行电流处理，减少了石墨烯中sp缺陷的数量。这些结果表明，对于电流处理过的钝化石墨烯（CTPG），高电流处理大大降低了带电杂质和俘获电荷密度，从而减少了库仑散射，同时减轻了碳原子的任何电迁移。我们的研究揭示了CTPG是一种可用于石墨烯纳米电子和自旋电子集成电路实际应用的创新系统。
