Construction and Multifunctional Photonic Applications of Light Absorption‐Enhanced Silicon‐Based Schottky Coupled Structures

Abstract To expand the detection capabilities of silicon (Si)‐based photodetector and address key scientific challenges such as low light absorption efficiency and short carrier lifetime in Si‐based graphene photodetector. This work introduces a novel Si‐based Schottky coupled structure by in situ growth of 3D‐graphene and molybdenum disulfide quantum dots (MoS ₂ QDs) on Si substrates using chemical vapor deposition (CVD) and plasma‐enhanced chemical vapor deposition (PECVD) techniques. The findings validate the “dual‐enhanced absorption” effect, enhancing the understanding of the mechanisms that improve optoelectronic performance. The synergistic effect of 3D‐graphene's natural nano‐resonant cavity and MoS ₂ QDs enhances light absorption efficiency and extends carrier lifetime. Introducing MoS ₂ QDs broadens and intensifies the built‐in electric field, promoting the separation of photogenerated electrons and holes. The photodetector exhibits a wideband light response in the wavelength range of 380–2200 nm. It stably outputs photocurrent under high‐frequency (1 kHz) modulated laser (2200 nm), with a responsivity (R) of 40 mA W ⁻¹ and detectivity (D ^* ) of 1.15 × 10 ⁹ Jones. Photodetectors show the ability to process and encrypt complex binary signals and achieve versatility in “AND” gate and “OR” gate logic operations, as well as image sensing (240 × 200 pixels).