Xue Boyu, Xiao Wei, Wan Guangyi, Yang Lunwei, Xie Haofeng, Wang Ligen
State Key Laboratory of Nonferrous Metals and Processes, China GRINM Group Co., Ltd., Beijing 100088, China.
GRIMAT Engineering Institute Co., Ltd., Beijing 101407, China.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):57524-57533. doi: 10.1021/acsami.4c12416. Epub 2024 Oct 14.
For graphene/copper (Gr/Cu) composites, achieving high-quality interfaces between Gr and Cu (strong interfacial bonding strength and excellent electron transport performance) is crucial for enabling their widespread applications in electronic devices. This study employs first-principles calculations and the nonequilibrium Green's function method to systematically investigate the mechanical and electrical conductivity properties of Cu(111)/Gr/Cu(111) interfaces with various stacking sequences and different forms of Gr. For these interface systems, the binding energy, separation work, charge transfer, and electrical conductivity across the interface were obtained. The results show that the top-fcc interface exhibits superior interfacial properties, characterized by relatively high binding energy (-3.00 eV/C atom) and separation work (≥0.78 J/m), a small interfacial distance (2.85 Å), and enhanced electron transport capacity (2.12 G/nm). A bilayer form of Gr significantly reduces electronic conductance across the Gr/Cu interface by nearly 2.46 orders of magnitude. Furthermore, point defects in Gr, especially single-vacancy defects, disrupt the traditional trade-offs between mechanical and electrical performance, simultaneously enhancing mechanical performance by 7.50-124.36% and electrical performance by 33.02%. Additionally, stress mechanisms have been proposed to further enhance the interfacial electrical conductivity of Gr/Cu composites. The present study provides a theoretical basis for exploring the engineering applications of Gr/Cu composite materials.
对于石墨烯/铜（Gr/Cu）复合材料而言，在Gr和Cu之间实现高质量界面（强界面结合强度和优异的电子传输性能）对于其在电子器件中的广泛应用至关重要。本研究采用第一性原理计算和非平衡格林函数方法，系统地研究了具有不同堆叠顺序和不同Gr形式的Cu(111)/Gr/Cu(111)界面的力学和导电性能。对于这些界面系统，获得了结合能、分离功、电荷转移和跨界面的电导率。结果表明，面心立方（fcc）顶层界面表现出优异的界面性能，其特征在于相对较高的结合能（-3.00 eV/C原子）和分离功（≥0.78 J/m）、较小的界面距离（2.85 Å）以及增强的电子传输能力（2.12 G/nm）。Gr的双层形式使Gr/Cu界面的电子电导显著降低了近2.46个数量级。此外，Gr中的点缺陷，特别是单空位缺陷，打破了传统的力学和电学性能之间的权衡，同时使力学性能提高了7.50 - 124.36%，电学性能提高了33.02%。此外，还提出了应力机制以进一步提高Gr/Cu复合材料的界面电导率。本研究为探索Gr/Cu复合材料的工程应用提供了理论依据。
