Fast growth of large-grain and continuous MoS 2 films through a self-capping vapor-liquid-solid method
Journal
Nature Communications
Journal Volume
11
Journal Issue
1
Date Issued
2020
Author(s)
Chang, M.-C.
Ho, P.-H.
Tseng, M.-F.
Lin, F.-Y.
Hou, C.-H.
Lin, I.-K.
Wang, H.
Huang, P.-P.
Chiang, C.-H.
Yang, Y.-C.
Wang, I.-T.
Du, H.-Y.
Wen, C.-Y.
Shyue, J.-J.
Chen, C.-W.
Chen, K.-H.
Chiu, P.-W.
Abstract
AbstractMost chemical vapor deposition methods for transition metal dichalcogenides use an extremely small amount of precursor to render large single-crystal flakes, which usually causes low coverage of the materials on the substrate. In this study, a self-capping vapor-liquid-solid reaction is proposed to fabricate large-grain, continuous MoS2 films. An intermediate liquid phase-Na2Mo2O7 is formed through a eutectic reaction of MoO3 and NaF, followed by being sulfurized into MoS2. The as-formed MoS2 seeds function as a capping layer that reduces the nucleation density and promotes lateral growth. By tuning the driving force of the reaction, large mono/bilayer (1.1 mm/200 μm) flakes or full-coverage films (with a record-high average grain size of 450 μm) can be grown on centimeter-scale substrates. The field-effect transistors fabricated from the full-coverage films show high mobility (33 and 49 cm2 V−1 s−1 for the mono and bilayer regions) and on/off ratio (1 ~ 5 × 108) across a 1.5 cm × 1.5 cm region.
SDGs
Type
journal article