Toward Ultimate Control of Terahertz Wave Absorption in Graphene

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

Abstract

It is commonly believed that weak light-matter interactions in low-mobility graphene dramatically limits tunability of graphene-based optoelectronic devices, such as tunable absorbers or switches. In this paper, we use a simple circuit model to understand absorption in graphene sheets. In particular, we show that light interacts weakly also with very high-mobility graphene sheets and propose systematic design means to overcome these problems. The results have allowed us to demonstrate in the terahertz band that perfect absorption with excellent electrical tunability can be achieved within a wide span of mobility values (from 200 to 20000 cm2V..1s..1) which almost covers the whole range of ever reported room-temperature mobilities. Remarkably, concentrating on the most practical low-mobility graphene devices, we exemplify our theory with two cases: frequencytunable and switchable absorbers with near 100% modulation efficiencies. Our work provides systematic and instructive insights into the design of highly tunable absorbers, without restrictions on graphene mobility. The design strategy and the developed analytical model can, in principle, be generalized to other wavelength regions from microwave to mid-infrared range, and other twodimensional materials such as transition metal dichalcogenides (TMDs) and black phosphorus.

Details

Original languageEnglish
Pages (from-to)2452-2461
JournalIEEE Transactions on Antennas and Propagation
Volume67
Issue number4
Early online date2018
Publication statusPublished - Apr 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Absorption, carrier mobility, Conductivity, Doping, frequency-tunable, Graphene, Graphene absorbers, Impedance, impedance control, Integrated circuit modeling, reconfiguration, Substrates, terahertz band

ID: 31120567