Li Wang, Shu-Juan He, Kui-Yuan Wang, He-Hao Luo, Ji-Gang Hu,* Yong-Qiang Yu, Chao Xie, Chun-Yan Wu, Lin-Bao Luo*

Abstract:High-performance photodetectors are desirable for various applications, including multi-wavelength image sensing, communication and safety monitoring. In this study, we report the construction of dual-surface plasmon enhanced silicon Schotty photodetector using Au nanoparticles (NPs)/graphene/Au NPs hybrid structure as electrode. It was found that the as-assembled device exhibited broad sensitivity ranging from ultraviolet to near-infrared light (360-1330nm) at room temperature, with high response speed of 360 ns and 3dB bandwidth of 780 kHz at zero bias. Further theoretical simulation based on finite-element method (FEM) revealed that the good device performance is associated with the contribution of the Au NPs/graphene/Au NPs electrode: Intense dual plasmonic resonance couplings is induced in hybrid structure of two layers metallic NPs separated by uniform monolayer graphene. It not only can enhance light trapping and the localized electric field at the resonant and off-resonant wavelength region, but also are beneficial for the tunneling of hot electrons. This work demonstrated the great potential of the dual plasmonic resonance couplings in optoelectronic devices and will lead to the development of advanced plasmonic devices.