Highly sensitive photodetector based on laser-generated graphene with 3D heterogeneous multiscale porous structures

[Display omitted] •Sub-microsecond transient photothermal processing of chemically-modified fluorinated polyimide using a laser creates heterogeneous micro-/nano-scale graphitic porous structures.•The heterogeneous multi-scale porous graphene structures enable a high specific surface area of 1309.7 m2 g−1 and optically resonant structures.•The high surface area and optically resonant structures of 3D graphene significantly enhance optical absorption, nearly reaching 100%, which is 33-fold higher than 2D graphene.•3D porous graphene photodetectors exhibit a 1000-fold improvement in photoresponsivity of 4.4 mA W−1 compared to 2D graphene detectors, along with a low Noise-equivalent power of 0.54 × 10−11 W Hz−1/2. Graphene holds great promise in optoelectronics because of its high broadband light absorption across a wide range of wavelengths. Despite low optical absorption, various techniques have been devised to address this challenge. This study presents a new highly sensitive, photodetector based on three-dimensional (3D) porous graphene derived from fluorinated polyimide (fPI-3DPG). This material is produced via a laser photothermal process and features micro- and nanopore structures that increase the light absorbing area and support optically resonant structures. The resulting fPI-3DPG photodetectors display high photoresponsivity of 4.4 mA W−1 in the visible light range, an ultrahigh signal-to-noise ratio of ∼208, and a noise equivalent power of 0.54 × 10−11 W Hz−1/2. These photodetectors are also mechanically durable, surviving 10,000 cycles of bending and twisting. The laser photothermal method used in this study enables fast, cost effective production of wearable and flexible optical sensors for imaging and spectroscopy applications, making this 3D graphene a promising functional material for sensing technologies.