Few-layered MoS2 Based Vertical van der Waals p-n Homojunction by Highly-efficient N-2 Plasma Implantation

2D transition metal dichalcogenides have shown great potential for next-generation microelectronic devices owing to their ability to prolong the life of Moore's law by mitigating the short-channel effect. Recently, many efforts have been made on doping 2D films to create p-n junctions, in which plasma implantation has been placed great expectations due to its CMOS process compatibility. However, ultrathin vertical 2D p-n homostructure with excellent rectification behaviors have rarely been studied so far. Herein, MoS2 van der Waals p-n homojunctions are fabricated by highly efficient N-2 plasma implantation. Kelvin probe force microscope reveals the surface potential difference of approximate to 130 mV between n-MoS2 and p-MoS2. The fabricated field-effect transistor (FET) presents a high rectification ratio up to 3.1 x 10(-3) at the gate bias V-GS = 20 V, which is over 20 times larger than that of the vertical homojunction obtained by surface chemical doping. The forward current is mainly dominated by both the interlayer recombination and band-to-band tunneling, while the ultra-low reverse current in the order of 10 pA is governed by direct tunneling. The results demonstrate a new CMOS-compatible way to fabricate vertical 2D homojunction, which is the basic structure of many low-dimensional microelectronic devices.