Synthesis of transfer-free graphene on an insulating substrate using a solid phase reaction

Abstract

We demonstrate a solid phase reaction approach to synthesise transfer-free graphene on an insulating substrate by controlling the C diffusion process. Metal assisted crystallization by annealing of a C thin film was carried out to synthesise transfer-free graphene, in the presence of a top metal oxide and metal layer. Without the metal oxide layer, a large amount of C atoms diffused to the top of the metal surface and hence the formation of only small graphene domains was observed on the underneath of the metal layer. Introducing the metal oxide layer at the top surface, C diffusion was reduced and consequently the thin C film was crystallized to form large area graphene at the metal-insulating substrate interface. The metal oxide or metal catalyst layer was removed after graphene formation and transfer-free graphene was obtained directly on the base substrate. This finding shows that the thin metal oxide layer is critical to synthesise graphene with better quality and continuous domain structures.

Growth of multi-layered graphene on molybdenum catalyst by solid phase reaction with amorphous carbon

“…After the anneal, all samples with the exception of Sample 2 exhibit the D-band (~1330 cm −1 ) and G-band (~1580 cm −1 ). Compared to the overall absence of any lattice structure, argued from the spectra in figures 3(a)-(g), the splitting of the singular peak into two clear separate bands indicates a hexagonal sp 2 structure, although disordered to some extent [16,23,24]. Sample 1 and Sample 4 also present the sharp 2D peak at around 2700 cm −1 , typically associated to the graphite-like materials.…”

“…Only a few attempts for starting from solid state carbon precursors have been reported so far [15][16][17].…”

Recent Development of the Transformation from Amorphous Carbon to Graphene Method via Metal Catalyst

“…峰宽化, 石墨烯的质量下降。Hirano 等 [39] 则利用 Co 作为催化剂, 在 Ar 条件下, 对比研究了 600℃和 800℃退火的实验结果, 发现 800℃退火时, Co 的催 化性能更优异, 获得石墨烯质量好。同样, Orofeo 等 [40] 也以 Co 和 Ni 作为催化剂, 厚度为 1 nm 的非 晶碳在 3.010 -4 Pa 气压下, 750~800℃退火温度范围 内得到的石墨烯质量最佳, 而 500℃退火得到的石 墨烯均一性较差。上述结果表明, 以金属 Co 和 Ni 为 催 化 剂 时 , 均 存 在 优 化 的 退 火 温 度 区 间 (600~ 800℃), 并且最佳退火温度在 750℃左右。为了进一 步研究退火温度对非晶碳转化生成石墨烯过程的影 响, Saenger 等 [41] 利用 XRD 进行分析, 结果显示以 金属 Ni 作为催化剂时, 非晶碳转化石墨烯的温度在 640~730℃; 在 600℃以上, 非晶碳会逐渐开始石墨 化; 而当温度高于 950℃时, 碳原子会再次溶进金 属 Ni 中, 进而使得到的石墨烯结构消失, 如图 7 所 示。与上述研究类似, 对于 Ni 体系来说, 的确存在 使非晶碳转化石墨烯质量最佳的温度区间。 图 7 不同厚度 Si/SiO 2 /a-C/Ni(100 nm)样品在 He 气氛下加 热至 1000℃及冷却过程中原位 XRD 的(002)石墨峰强等高线 图, 变温速率为 3℃/s, 厚度(a) 3 nm、(b) 10 nm 和(c) 30 nm。 不同厚度 a-C 样品的等高线间隔不同 [41] Fig. 7 Contour maps of in situ XRD results showing the 002 graphite peak in Si/SiO 2 /a-C/Ni (100 nm) samples heated to and cooled from 1000℃ in He at a ramp rate of 3℃/s for a-C thicknesses of (a) 3 nm, (b) 10 nm, and (c) 30 nm.…”

Chemical vapor deposition of graphene on silver foil as a tarnish‐resistant coating

“…In a CVD process the catalytic decomposition of hydrocarbons on transition metals is the most promising approach to grow a continuous graphene film 10, 11. Among transition metals, nickel, copper and cobalt have been significantly investigated as a catalytic layer to achieve high‐quality graphene growth 6–8, 12, 13. Similarly, other metals, such as ruthenium, iridium, platinum and palladium have been also investigated as a substrate material for graphene synthesis in a CVD process 14–16.…”