Rational Design on Wrinkle-Less Transfer of Transition Metal Dichalcogenide Monolayer by Adjustable Wettability-Assisted Transfer (AWAT) Method

Ying-Chun Shen^1*, Yu-Ting Wu², Po-Wen Chiu², Yu-Lun Chueh¹

¹Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
²Institute of Electronics Engineering, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Ying-Chun Shen, email:kuroekyo@gmail.com

Transfer-induced wrinkles are universal issues when transferring transition metal dichalcogenide (TMDC) monolayer from an as-grown substrate to a target substrate. The undesired transfer-induced wrinkles can mainly be attributed to wettability, which refers to the ability of a liquid to come in contact with a solid surface. Herein, we developed an adjustable wettability-assisted transfer (AWAT) method with different mixtures of transfer media to reduce the density of wrinkles to the target substrate. By manipulating the wettability of the transfer medium with different ratios of alcohol and DI water, the TMDC monolayer was smoothly attached to the target substrate, thus achieving a wrinkle-less transferred TMDC monolayer. With this method, the density of wrinkles can be decreased by ~15–20 % compared with the conventional transfer method by pure DI water. The transferred MoS₂ monolayer with the AWAT method can achieve enhanced carrier mobility from ~20 to ~35 cm²V^-1s^-1 in average, which is 30 times larger than that transferred with the conventional transfer method by the pure DI water.

Keywords: wet transfer, wettability, transition metal dichalcogenides materials, wrinkle-less