A modified wrinkle-free MoS film transfer method for large area high mobility field-effect transistor.

Wrinkle-free transfer of chemical vapor deposition (CVD) synthesized 2D MoS is a prerequisite for large-area high-performance device fabrication. The surface-energy-assisted transfer method is a suitable method for MoS transfer, which greatly reduces the damage to the MoS. However, in the process of tiling the MoS to the new substrate, droplets are sandwiched between the MoS and substrate, which are difficult to remove and easily cause wrinkles and cracks. To avoid the realization of wrinkles and cracks in the transfer, we developed a modified surface-energy-assisted transfer method that modifies the spreading parameter S of residual droplets sandwiched between the MoS and substrate. By using this strategy, the liquids were easily to remove from the MoS/substrate interface resulting in a smooth MoS film with no wrinkles. Larger area back-gated field-effect transistor (FET) arrays were also fabricated based on the transferred monolayer MoS (10 × 10 mm) with atomic layer deposition prepared HfO as the high-k gate insulator. The FETs exhibited a high on/off ratio of 10 and carrier mobility up to 118 cm V s, which is the highest mobility values reported for back-gate transistors fabricated with CVD synthesized MoS. This transfer method provides a useful strategy for the fabrication of larger area high property FETs on MoS.