Photothermal Conversion and Fast Response Properties of 3D Graphene Foam in the Terahertz Range

Abstract

Fast terahertz response of three dimensional graphene foam through photothermoelectric effect is reported in this work with its photothermal conversion property investigated by infrared thermal imaging. A great temperature rise of 70 K (1.25 W/cm2, 2.52 THz) was obtained with a small thermal diffusion length scale of 0.7 mm and a short response time of 21 ms. This material can be used as an ideal absorber for terahertz thermal detector and experiment results proved that the photothermoelectric response of a single-layer graphene can be enhanced six times with a small block of three dimensional graphene foam adhering to it.