Strain‐Enhanced and Waveguide‐Integrated Electroluminescence from a 2D Monolayer Semiconductor

Abstract Toward integrated optoelectronic circuits, electrically‐driven nanoscale light sources remain a key challenge in nanophotonics. 2D monolayer semiconductors, especially transition metal dichalcogenides (TMDs) represent as promising materials for developing room‐temperature tunable exciton light sources, where their exciton emission behaviors can be well controlled via strain engineering. Here, strain‐enhanced electroluminescence (EL) is demonstrated from monolayer tungsten diselenide (WSe 2 ), which is further coupled to an optical waveguide for signal transmission. Under the alternating current (AC) gate voltage, EL emission is collected from the monolayer WSe 2 and the light emission is selectively enhanced at the local strained position due to the exciton funneling effect. Furthermore, using a molybdenum trioxide (MoO 3 ) nanoribbon as both the strain source and the optical waveguide, strain‐confined and waveguide‐integrated EL emission is visualized from the monolayer WSe 2 with a coupling efficiency of 5.7%. The work provides new insights for realizing electrically‐driven on‐chip light sources based on monolayer semiconductors.