Defect-induced photocurrent gain for carbon nanofilm-based broadband infrared photodetector

Abstract

Broad-spectrum detection and large-scale integration are the inevitable trends in the current evolution of infrared photodetectors. New materials were integrated with existing platforms to further improve the performance of infrared photodetectors. Here, we reported a defective macro-assembled graphene nanofilm (D-nMAG)/Silicon (Si) photodetector using trap-assisted gain to optimize the photoelectric response. This wafer-scale environmentally friendly carbon material can be easily compatible with the complementary-metal-oxide-semiconductor (CMOS) technical. Noteworthy, the defective states in D-nMAG trap carriers and then enter the conduction (CB) and valence band (VB) again to be thermalized, generating a gain in photocurrent. Thus, our D-nMAG-based line array image sensor exhibits high-resolution infrared imaging of the target. This device displays a high responsivity at room temperature within a broad-spectrum region, i.e., 0.156 A/W @ 900 nm in the near-infrared (NIR) region and 3.7 mA/W @ 4 μm in the mid-infrared (MIR) region. Our work provides a carbon nanofilm for IR detection at a broad-spectrum region, with tunable defective structure, uniform thickness, and wafer-scale production.