Silane-catalysed fast growth of large single-crystalline graphene on hexagonal boron nitride

Abstract

The direct growth of high-quality, large single-crystalline domains of graphene on a dielectric substrate is of vital importance for applications in electronics and optoelectronics. Traditionally, graphene domains grown on dielectrics are typically only ~1 μm with a growth rate of ~1 nm min−1 or less, the main reason is the lack of a catalyst. Here we show that silane, serving as a gaseous catalyst, is able to boost the graphene growth rate to ~1 μm min−1, thereby promoting graphene domains up to 20 μm in size to be synthesized via chemical vapour deposition (CVD) on hexagonal boron nitride (h-BN). Hall measurements show that the mobility of the sample reaches 20,000 cm2 V−1 s−1 at room temperature, which is among the best for CVD-grown graphene. Combining the advantages of both catalytic CVD and the ultra-flat dielectric substrate, gaseous catalyst-assisted CVD paves the way for synthesizing high-quality graphene for device applications while avoiding the transfer process.

Large area CVD growth of graphene

“…Without the catalyst effect from transition metals, graphene can be synthesized on insulating substrates, such as MgO [96], SiO 2 [97,98], sapphire [34,99], h-BN [100][101][102][103][104] with various carbon source, such as acetylene [96], ethylene [98], and methane [97,99]. Mostly, such samples grown on insulating substrates have larger defect-related Raman D peak compared to those prepared on metal surfaces.…”

Edge control of graphene domains grown on hexagonal boron nitride

“…A precise control of the grain shape and crystallinity on h-BN requires either a plasma-enhanced approach 19 or gaseous catalyst assisted growth. 10 Our recent progress in silane-assisted growth exhibits its advance in growth of single-crystal graphene domains, 10 where Si element acts as a carbon activator while hydrogen plays as etching element. As such, silane can play a crucial role in the determination of the shape and size of graphene domains.…”

Decoupling of graphene from Ni(111) via formation of an interfacial NiO layer

“…For example, implementation of graphene in the present-day scalable semiconducting technology requires its synthesis on insulating or semiconducting substrates. Presently this is only possible on h-BN [7][8][9][10] and Ge [11][12][13][14][15] substrates at the conditions which cannot be easily adapted.…”