Highly efficient plasmon excitation in graphene-Bi_2Te_3 heterostructure

Abstract

Graphene plasmons have attracted a lot of attention due to large confinement and small mode volume. However, the graphene-based plasmonic devices are still limited in the practical applications due to relatively small light absorption of graphene and limited light-matter coupling efficiency in general excitation strategy. Here, this work reported a strong plasmonic coupling effect observed in a novel graphene-Bi 2 Te 3 heterostructure on the top of silicon gratings. It is interesting to find that the extinction spectra of the graphene-Bi 2 Te 3 heterostructure has shown three times greater magnitude than that of graphene. This observation is mainly attributed to two factors: first, the coupling efficiency between the graphene and Bi 2 Te 3 second, the higher light absorption in the graphene-Bi 2 Te 3 heterostructure. Moreover, the plasmonic resonance peak of the graphene-Bi 2 Te 3 heterostructure can be easily tuned by changing the grating period just like what happens in the graphene film. In all, this work utilizes the simple silicon grating to couple the light into the graphene-Bi 2 Te 3 heterostructure, and further explores the hybridized Dirac plasmons in the graphene-Bi 2 Te 3 heterostructure. We believe it will stimulate the interest to study the variant plasmonic heterostructure and trigger new terahertz device applications. Graphene plasmons have attracted a lot of attention due to large confinement and small mode volume. However, the graphene-based plasmonic devices are still limited in the practical applications due to relatively small light absorption of graphene and limited light-matter coupling efficiency in general excitation strategy. Here, this work reported a strong plasmonic coupling effect observed in a novel graphene-Bi 2 Te 3 heterostructure on the top of silicon gratings. It is interesting to find that the extinction spectra of the graphene-Bi 2 Te 3 heterostructure has shown three times greater magnitude than that of graphene. This observation is mainly attributed to two factors: first, the coupling efficiency between the graphene and Bi 2 Te 3 ; second, the higher light absorption in the graphene-Bi 2 Te 3 heterostructure. Moreover, the plasmonic resonance peak of the graphene-Bi 2 Te 3 heterostructure can be easily tuned by changing the grating period just like what happens in the graphene film. In all, this work utilizes the simple silicon grating to couple the light into the graphene-Bi 2 Te 3 heterostructure, and further explores the hybridized Dirac plasmons in the graphene-Bi 2 Te 3 heterostructure. We believe it will stimulate the interest to study the variant plasmonic heterostructure and trigger new terahertz device applications.

In situ Optical Study of Gold Nanorod Coupling with Graphene

“…While the thickness of graphene is too atomically thin to absorb sufficient light, which inevitably restricts its efficient applications. The combination of graphene with metal nanostructures or topological insulator can significantly enhance the light–matter interaction in visible and near‐infrared . These hybrid structures show plasmonic electrical effects including an improved photogeneration rate, efficient carrier transfer, and a plasmon‐induced hot electrons.…”

Absorption enhancement and total absorption in a graphene-waveguide hybrid structure

“…In the mid-IR to THz wavelengthes, doped graphene with negative effective permittivity acts like ultrathin metals, and surface plasmonic polaritons (SPPs) can be excited due to coupling of incident light and electrons in graphene. 10 The excitation of SPPs will cause strong field enhancement near graphene, and strong absorption of graphene can be realized. This method has been widely studied to realize absorption enhancement or even total absorption for graphene strips, 11,12 nano disks 13,14 and metamaterials.…”

Hybrid Plasmonics and Two-Dimensional Materials: Theory and Applications

“…66 71 Moreover, coupling Bi 2 Te 3 with graphene enhances the plasmon excitation in graphene. 72 Other interesting materials with plasmonic properties are 2D oxides of tungsten and molybdenum. 73 They can be ultra-doped and have also large dielectric constants.…”