Simulation to fabrication—understanding the effect of NiAuCu alloy catalysts for controlled growth of graphene at reduced temperature
Simulation to fabrication—understanding the effect of NiAuCu alloy catalysts for controlled growth of graphene at reduced temperature
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DOI：
10.1088/2053-1591/ab5bc3
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发表时间：
2019-11
影响因子：
2.3
通讯作者：
H. Zhan;B. Jiang;O. Zietz;Sam Olson;J. Jiao
中科院分区：
文献类型：
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作者：
H. Zhan;B. Jiang;O. Zietz;Sam Olson;J. Jiao
在低温下生长大规模、高质量的单层石墨烯对于工业应用，特别是对于互补金属氧化物半导体制造工艺来说是一个重大挑战。为了克服这一困难，我们使用 4 × 4 × 4 周期超晶胞模型模拟了乙炔 (C2H2) 在含有少量金 (Au) 和铜 (Cu) 的主要镍 (Ni) 催化剂的 (100) 表面上的分解。基于不同催化剂表面上分解C-H或C=C键的反应能量的计算，提出了微分能量来清楚地衡量分解的难度，使得更大的微分能量导致更容易控制单层生长。结果表明，在Au和Cu摩尔分数均为0.0313的NiAuCu合金表面，C-H键和C≡C键的差能均为正，对C2H2的分解和催化活性表现出明显的调节作用。模拟结果与采用 C2H2 前驱体和含 1 wt% Au 和 1 wt% Cu 的 Ni 合金催化剂在 500°C 下通过等离子体增强化学气相沉积在二氧化硅基底上生长均匀单层石墨烯的结果一致。
It is a significant challenge to grow large-scale, high quality, monolayer graphene at low temperature for the applications in industry, especially for the complementary metal oxide semiconductor fabrication process. To overcome this difficulty, we simulated the decomposition of acetylene (C2H2) on (100) surfaces of primarily nickel (Ni) catalysts with small mol fractions of gold (Au) and copper (Cu), using a 4 × 4 × 4 periodic supercell model. Based on the calculation of the reaction energies to decompose the C-H or C≡C bonds on different catalyst surfaces, a differential energy is proposed to clearly scale the decomposition difficulties such that larger differential energy leads to easier control of the monolayer growth. It is observed that on the NiAuCu alloy surface with a mol fraction 0.0313 of both Au and Cu, the differential energy of the C-H bonds and the C≡C bond are both positive, showing an obvious modulation effect on the decomposition of C2H2 and the catalytic activites. The simulation result is consistent with the growth of uniform monolayer graphene on silicon dioxide substrate at 500°C by plasma enhanced chemical vapor deposition with C2H2 precursor and Ni alloy catalysts with 1 wt% Au and 1 wt% Cu.