Dielectric engineered graphene transistors for high-performance near-infrared photodetection

Graphene, known for its ultrahigh carrier mobility and broadband optical absorption, holds significant potential in optoelectronics. However, the carrier mobility of graphene on silicon substrates experienced a marked decrease due to surface roughness, phonon scattering affects. Here we report carrier mobility enhancement of graphene dielectric engineering. Through the fabrication of devices utilizing Si/SiO₂/Al₂O₃/graphene layers and subsequent electrical characterization, our findings illustrate the navigable nature of the Al₂O₃ dielectric layer is navigable for reducing the SiO₂ phonon scattering and increasing graphene's carrier mobility by up to ∼8000 cm²V^-1s^-1. Furthermore, the improvement in carrier mobility of graphene has been utilized in the hybrid near-infrared photodetector, resulting in outstanding responsivity of ∼400 AW^-1, detectivity of ∼2.2 ✕ 10¹¹ Jones in the graphene/Ag₂Te detector. Our study establishes pathways for the seamless integration of graphene or other 2D materials within the standard CMOS processes, thereby facilitating the fabrication of advanced optoelectronic devices.