Sub-terahertz radiation detection using graphene noise thermometry method

In this paper we investigate a novel approach to inventing graphene-based sub-terahertz bolometers using noise thermometry. Graphene is a unique material for detecting radiation in the sub-terahertz (0.1–1 THz) and terahertz (1–10 THz) ranges due to its record low electron heat capacity and weak electron-phonon coupling. This results in sufficient heating of graphene electron system under terahertz radiation. The main challenge in the realization of graphene terahertz detectors arises due to weak graphene resistance dependence on temperature. Here, we solve this problem by measuring noise spectral density in graphene devices using lock-in amplifier technique under radiation of 0.13 THz. The measured thermal noise is directly dependent on electron temperature and can be used as detector signal as well as probe of electron temperature under sub-terahertz radiation. The obtained experimental data can be used to optimize modern graphene terahertz detectors and develop new ones.