Image-force barrier lowering in top-and side-contacted two-dimensional materials

摘要: We compare the image-force barrier lowering (IFBL) and calculate the resulting contact resistance for four different metal–dielectric-two-dimensional (2D) material configurations. We analyze edge contacts in three different geometries (a homogeneous dielectric throughout, including the 2D layer; a homogeneous dielectric surrounding the 2D layer, both ungated and back gated) and also a top-contact assuming a homogeneous dielectric. The image potential energy of each configuration is determined and added to the Schottky energy barrier which is calculated assuming a textbook Schottky potential. For each configuration, the contact resistivity is calculated using the WKB approximation and the effective mass approximation using either SiO 2 or HfO 2 as the surrounding dielectric. We obtain the lowest contact resistance of 1 k Ω μ m by n-type doping an edge contacted transition metal-dichalcogenide (TMD …