Here, I am going to introduce our strategies to produce 2DMs via top-down and bottom-up approaches. At first, I will present a scalable growth of single-crystal graphene (SCG) on through "transplanting” uniaxially aligned graphene “seedlings" on the larger-area catalytic growth substrate. By inducing homo-epitaxial growth of graphene from the edges
of the seed arrays without additional nucleation, we achieved the SCG with an area four times larger than the mother graphene seed substrate. And then, I will introduce atomic spalling of the van der Waals crystals that achieve large area 2DMs (graphene, MoS2, MoSe2, and WSe2) with a controlled number of layers. We found that being a layered crystal with a weak interlayer vdW force enables to control of the crack propagation depth at the scale corresponding to the single atomic thickness by adjusting interfacial toughness and the internal stress of the stressor film. The results show huge potential to produce layer-resolved high-quality vdW materials, which can be developed into practical functional electronic and photonic devices.