DC-operated near-infrared light emitting diode based on MOCVD-grown WSe2 monolayers

Monolayer transition metal dichalcogenides (TMDC) combine huge oscillator strength with naturally terminated surfaces, enabling optoelectronic devices on various platforms. Despite numerous efforts to integrate 2D materials in light-emitting devices, a scalable direct current (DC) driven near-infrared 2D material-based (NIR) emitter has not been reported yet. In this work, a large-area, DC-operated NIR light-emitting device based on WSe 2 monolayers grown by metal-organic chemical vapor deposition (MOCVD) is presented. Our scalable device architecture enables a diode-like I–V curve with a rectifying ratio exceeding 20 and a turn-on voltage of ~1.5 V, indicating excellent electrical performance. NIR electroluminescence at 778 nm is observed at 1.5 V, along with a radiance of ~2 µW cm −2 sr −1 at 5 V under DC operation.