High performance ambipolar MoS2 transistor enabled by indium edge contacts.

Integration of electrical contact into two-dimensional heterostructure is an essential key to approach high-quality electronic nano-devices, especially field-effect transistors. However, high contact resistance with transition metal dichalcogenides such as molybdenum disulphide (MoS2) based devices has been a significant fabrication impediment to their potential applications. Here, we have demonstrated the advantage of one-dimensional indium metal contact with fully encapsulated MoS2within hexagonal boron nitride. The electrical measurements of device exhibit ambipolar transport with an on/off ratio of 104for holes and 107for electrons. The presence of ambipolar transport in MoS2illustrates that the pinned Fermi level of MoS2has been de-pinned to some extent by virtue of indium edge contact, thus enabling us to access electrons as well as holes. The device exhibits high field-effect mobility of 40.7 cm2V-1s-1at liquid nitrogen temperature. Further, we have also analysed the charge transport mechanism at the interface and have calculated the Schottky barrier height from the temperature-dependent measurement. These results are highly promising for the use of air sensitive materials heterostructure and large-scale design of trending flexible, transparent electronic wearable devices.