Self-screened high performance multi-layer MoS2 transistor formed by using a bottom graphene electrode

摘要

We investigated the carrier transport in multi-layer MoS2 with consideration of the contact resistance (R-c) and interlayer resistance (R-int). A bottom graphene contact was suggested to overcome the degradation of I-d modulation in a back gated multi-layer MoS2 field effect transistor (FET) due to the accumulated R-int and increased R-c with increasing thickness. As a result, non-degraded drain current (I-d) modulation with increasing flake thickness was achieved due to the non-cumulative R-int. Benefiting from the low R-c induced by the negligible Schottky barrier at the graphene/MoS2 interface, the intrinsic carrier transport properties immune to R-c were investigated in the multi-layer MoS2 FET. similar to 2 times the enhanced carrier mobility was attained from the self-screened channel in the bottom graphene contacted device, compared to those with top metal contacts.