Terahertz photonic applications of two-dimensional materials

Broadband terahertz (THz) electromagnetic waves sensitively respond to intra- and intermolecular vibration modes of various molecules, showing excellent potential applications in many areas such as optoelectronics, photonics, spectroscopy, and microscope. Besides, very low photon energy of several meV allows direct monitoring of the intrinsic characteristics of 2D (two-dimensional) materials without interband interaction. It is also highlighted for its advanced device performance and increased efficiency by combining with nanotechnology and newly developed materials. Recently, graphene-based THz device applications using graphene plasmon resonances have been introduced and intensively explored in terms of THz modulation, detection, and emission. By combining with 2D materials and metamaterials, which have extreme subwavelength structures in the order of 10-/10, 000, the strongly enhanced and well-controlled THz field can be used for increasing the detection sensitivity and selectivity as well. Expanded applications including advanced THz shielding performance using highly absorptive materials such as MXene and its control can be also expected.