Homogeneous in-plane WSe2 P–N junctions for advanced optoelectronic devices

Through selective plasma doping, the in situ construction of homogeneous lateral WSe 2 P–N junctions within a single WSe 2 flake is achieved. Our device shows an external quantum efficiency of ∼228% and a high photoresponsivity of ∼7.1 × 10 4 mA W −1 .