Graphene-based terahertz optoelectronics

Graphene is a new material with a single-layer two-dimensional (2D) honeycomb lattice structure. It has excellent optical, electrical and mechanical properties, and it is closely linked with terahertz (THz) science and technology by regulating the properties of graphene. This article reviews THz optoelectronic devices based on graphene materials, including THz lasers, modulators, detectors, and phase shifters. It first introduces the growth, transfer and patterning process of graphene and the points paid attention in related processes, and then analyzes the interaction mechanism between graphene and THz waves from the perspective of optical physics. Next it introduces the methods to improve the performance of graphene THz optoelectronic devices, such as dual/multilayer graphene structures, split ring resonators (SRRs), field effect transistors (FETs), coupled an-tennas, micro-cavity structures, and resonant cavity arrays. Then it summarizes the performance of graphene THz optoelectronic devices. By comparing graphene-based THz optoelectronic devices with traditional THz optoelectronic devices, it can be seen that graphene THz optoelectronic devices have excellent performance in terms of output band width, detection band width, responsivity, sensitivity, and noise equivalent power (NEP). Finally, it points out the problems and shortcomings in the performance of graphene-based THz optoelectronic devices, and proposes methods to improve the device performance, which provides ideas and directions for the further development of THz optoelectronic devices in the future.