Influences of Contact Metals on the Performances of MoS₂ Devices under Strains

Abstract

The growth of large-area MoS₂ films was achieved through atmospheric pressure chemical vapor deposition via vapor management in this study. The thickness of the MoS₂ film changed upon varying the amount of vapor deposited on the substrate. Gratifyingly, large-area monolayer MoS₂ was obtained under controlled conditions. Studies using transmission electron microscopy and second harmonic generation confirmed that the MoS₂ films were composed of grains having sizes ranging from 40 to 70 μm. Flexible MoS₂ device arrays were fabricated on a polyimide substrate; the device arrays displayed high spatial uniformity in their carrier transport properties. The contact metals affected the electrical characteristics of the MoS₂ devices under strain; the sensitivity of devices featuring Schottky contacts was higher than that of those with ohmic contacts. Importantly, the device arrays exhibit sensitive and endurance performances under strain cycles of up to 10⁵ times. These results suggest a means for the feasible growth of large-area single-layer MoS₂ films, as well as the exploitation of flexible MoS₂ device arrays in strain and human motion sensor applications.