Superionic Modulation of Polymethylmethacrylate-Assisted Suspended Few-Layer Graphene Nanocomposites for High-Performance Photodetectors

Graphene is receiving significant attention for use in optoelectronic devices because it exhibits a wide range of desirable electrical properties. Although modified graphene that is fabricated on quantum dots (or similar integration strategies) has shown promise, it has not met the requirements for high-speed applications and highly sensitive detection. Herein, we report ion-modulated graphene composite nanostructures that were incorporated into photodetectors. We focus on the dynamical properties of the novel photodetectors, and they exhibit extraordinary photoelectric performances (photoresponsivity ∼1 A/W, response time ∼100 μs) over a broad range of wavelengths from 405 to 1064 nm (the maximum external quantum efficiency is greater than 300% at 635 nm with a 10 kHz chopping frequency). A theoretical model is proposed in this paper, and it is in good agreement with our experimental results. The dynamic analyses further confirmed the dissociation and recombination of ion-electron bound states to be responsible for the fast and sensitive photoresponse from the composite samples. Although ion-modulated optoelectronic nanomaterials are rarely studied, they require further exploration as they offer new insights and alternatives in nanomaterial research.