Abstract
Components smaller than the wavelength of electromagnetic waves are called meta-atoms. Thermal emission can be controlled by an artificial structure in which these meta-atoms are arranged on the surface. This artificial structure is called a metasurface, and its optical properties are determined by the materials and shapes of the meta-atoms. However, optical devices may require active control of thermal emission. In the present study, we theoretically and numerically analyze a wavelength-selective emitter using a graphene ribbon metasurface. The graphene ribbon metasurface consists of a graphene ribbon array, potassium bromide thin film, and silver substrate. The geometric parameters of the graphene metasurface are determined based on an equivalent circuit model that agrees well with the results of the electromagnetic field analysis (rigorous coupled-wave analysis). The proposed emitter causes impedance matching depending on the conductivity of the graphene ribbon in a very narrow wavelength range. The conductivity of graphene can be actively controlled by the gate voltage. Therefore, the proposed emitters may realize near-perfect emission with a high quality factor and active controllable switching for various wavelengths. In addition, the quality factor can be changed by adjusting the electron mobility of graphene. The proposed emitter can be used for optical devices such as thermophotovoltaic systems and biosensing.
Highlights
Thermal emission is a spontaneous and continuous photon emission from the thermal reservoir [1]
Active switching of narrow-band thermal emission is a key technology with applications in thermophotovoltaic systems [3,4], infrared heaters [5], biosensing [6,7,8], microbolometers [9,10], imaging [11], and optical communications [12]
We focus on graphene, which is one of the carbon and has honeycomb structure where carbon atoms are to bonded twoIn the allotropes, present study, wea propose a graphene ribbon metasurface design a device dimensionally
Summary
Thermal emission is a spontaneous and continuous photon emission from the thermal reservoir [1]. Thermal emission cannot be actively controlled by conventional metasurfaces To solve this problem, we focus on graphene, which is one of the carbon allotropes, and has a honeycomb structure where carbon atoms are bonded two of 13 dimensionally [16]. Active switching of thermal emission may be possible without changing the shape of the structure using graphene metasurfaces [17,18]. Fermi ofgraphene graphene.ribbon metasurface can exhibit putationally the energy designed near-perfect narrow-band thermal emission under active switching using electromagnetic. The equivalent circuit model is useful for designing graphene ribbon metasurfaces and elucidating the underlying mechanism of emissivity enhancement [22]. There are two restrictions in determining the structural parameters: (1) the graphene ribbon width must not exceed the period; (2) because of the effectiveness of the equivalent circuit model, the period must not exceed the wavelength.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
