Publications
MoS 2 -OH Bilayer-Mediated Growth of Inch-Sized Monolayer MoS 2 on Arbitrary Substrates
Due to remarkable electronic property, optical transparency, and mechanical flexibility, monolayer molybdenum disulfide (MoS 2 ) has been demonstrated to be promising for electronic and optoelectronic devices. To date, the growth of high-quality and large-scale monolayer MoS 2 has been one of the main challenges for practical applications. Here we present a MoS 2 -OH bilayer-mediated method that can fabricate inch-sized monolayer MoS 2 on arbitrary substrates. This approach relies on a layer of hydroxide groups (aOH) that are preferentially attached to the (001) surface of MoS 2 to form a MoS 2 -OH bilayer structure for growth of large-area monolayer MoS 2 during the growth process. Specifically, the hydroxide layer impedes vertical growth of MoS 2 layers along the [001] zone axis, promoting the monolayer growth of MoS 2 , constrains growth of the MoS 2 monolayer only in the lateral direction into larger area, and effectively reduces sulfur vacancies and defects according to density functional theory calculations. Finally, the hydroxide groups advantageously prevent the MoS 2 from interface oxidation in air, rendering high-quality MoS 2 monolayers with carrier mobility up to ∼30 cm 2 V -1 s -1 . Using this approach, inch-sized uniform monolayer MoS 2 has been fabricated on the sapphire and mica and high-quality monolayer MoS 2 of single-crystalline domains exceeding 200 μm has been grown on various substrates including amorphous SiO 2 and quartz and crystalline Si, SiC, Si 3 N 4 , and graphene This method provides a new opportunity for the monolayer growth of other two-dimensional transition metal dichalcogenides such as WS 2 and MoSe 2 .