Active Modulation of Graphene Near‐Infrared Electroabsorption Employing Borophene Plasmons in a Wide Waveband

Abstract

The unique optical and electronic properties of 2D materials make them suitable for the design of novel optoelectronic devices with ultracompact sizes, exhibiting great potential for major advances in the state of art of existing techniques. Here, for the first time, a prototype of a modulator is theoretically presented for the active modulation of graphene electroabsorption enabled by the tunable anisotropic borophene plasmons. Simulations reveal that the strong localized electrical field induced by borophene plasmons can significantly improve the graphene electroabsorption, of which the center wavelength can be further dynamically controlled by gate tuning the resonant wavelength of borophene plasmons. Then by gate tuning the graphene Fermi energy to transform graphene between a lossy and a lossless material, electrically switched absorption of graphene with modulation depth of 100% can be realized within a wide waveband in the near‐infrared region, including the commercially important telecommunication wavelength of 1.55 µm, indicating the excellent performance of the designed modulator via such mechanism. Such wavelength‐tunable graphene electroabsorption modulation strategy based on borophene plasmons provides an effective method for the design of graphene‐based selective multichannel switches or modulators, which is unavailable in previous reported strategies that can be only realized by passively changing the structural parameters.

Promoting 2D Material Photodetectors by Optical Antennas beyond Noble Metals

“…In addition to the above‐mentioned optical antennas that have been extensively exploited for 2DLM photodetectors, a number of neoteric non‐noble plasmonic active competitors with intense LSPR effects have also emerged in the past few years including carbon nanotube, [ 213 ] graphene, [ 214,215 ] NbSe 2 , [ 64 ] TaSe 2 , [ 216 ] WTe 2 , [ 217 ] GeSe, [ 218 ] TiS 2 , [ 219 ] borophene, [ 220 ] NiSe, [ 92 ] CoSe, [ 92 ] MoN, [ 221 ] TiN, [ 222,223 ] ZrN, [ 224 ] Sb 2 Te 3 , [ 112 ] Bi 2 Te 3 , [ 225 ] silicon, [ 226,227 ] germanium, [ 228 ] bismuth, [ 229 ] tellurium, [ 230 ] GaP, [ 231 ] etc. These fascinating materials have shown indisputable prospects for enhancing the light–matter coupling.…”

Tunable strong plasmon–exciton coupling based modulator employing borophene and deep subwavelength perovskite grating

“…The optimized geometrical parameters P (period), w (width), and h (height) are set as 20, 10, and 20 nm, respectively. The permittivity of the borophene is calculated via [27],…”

“…Fortunately, borophene, as an emergent 2D material, supports the plasmonic mode in the visible region owing to its high electron density (∼10 19 m −2 ) [26]. Moreover, the borophene plasmon with extrasmall mode volume could be flexibly controlled to manipulate the plasmon-exciton hybridized process [27,28]. Combined with the borophene and perovskite, the tunable strong plasmon-exciton coupling will be a desired platform to investigate the light-matter interaction at room temperature.…”

Low-Threshold and High-Extinction-Ratio Optical Bistability within a Graphene-Based Perfect Absorber

“…However, the interaction between light and monolayer graphene is very weak due to the ultrathin thickness of graphene, which seriously limits the applications of graphene in the optical field. In order to greatly enhance the light-graphene interaction, many kinds of graphene-based resonators [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ] and perfect absorbers [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ] have been proposed, and some applications of those structures have been demonstrated [ 35 , 36 , 37 , 38 , 39 ]. Until now, OB in graphene-based resonators has been theoretically and numerically studied [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ].…”