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.