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

Abstract

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. ∼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.