Enhancement of Terahertz-Induced Photothermoelectric Effect in a Carbon Nanotube Fiber by 3D Porous Graphene

摘要

Carbon nanomaterials have been proven to show considerable photothermoelectric (PTE) effects that can be used for photodetection, especially for the terahertz range where high performance detectors are highly desired at present. For the PTE effect occurring in carbon nanomaterials, the responsivity and speed usually compete with each other due to the substrate influence. The substrate with a low thermal conductivity leads a strong photoresponse due to the more heat accumulation, but a slow response speed due to the longer thermal equilibrium time. In this work we report on the improvement of the PTE response of a carbon nanotube fiber under terahertz illumination by using 3D porous graphene as the substrate benefiting from its perfect absorption to terahertz radiation and fast thermal diffusion process. About ten times enhancement of the responsivity and five times increase in response speed were observed in a preliminary experimental demonstration. Our work paves the way to develop high performance carbon nanomaterial-based terahertz PTE detectors.