Near-infrared electroluminescence and self-powered photodetector based on graphene/layered γ-InSe Schottky junction

The multifunctional integrated on-chip near-infrared (NIR) light source and detection devices based on vdW layered materials are increasingly sought after due to their broad applications, including optoelectronic communication, computing, and sensing. Most of luminescence or detection devices based on vdW layered materials are demonstrated to have only a single function due to the limitation of material properties. Here, we demonstrated a multifunctional integrated on-chip NIR electroluminescence (EL) and self-powered photodetector (SPPD) device constructed by stacking few-layer graphene (Gr) and layered γ-InSe to form asymmetric Gr/γ-InSe/Gr heterostructure. Room temperature electrically driven NIR from γ-InSe was successfully achieved by the high quality Schottky junction (rectification ratio up to "5×" 〖"10" 〗^"3" ), with a turn-on voltage of ~ 1.4 V. The γ-InSe EL maintained over 90 % initial EL intensity after two hours continuous operation in air. Meanwhile, the Gr/γ-InSe/Gr SPPD exhibits a broad spectrum photoresponse (405-940nm), low specific noise current (8.7"×" 10-26 A2/Hz), high specific detectivity (~ 108 Jones @ 405 nm) and high-quality reflective imaging. Our results establish a simple preparation and tunable vdW layered material multifunctional integrated NIR EL and SPPD device, indicating the promise of γ-InSe for on-chip integrated optoelectronic devices.