High Q Resonant Graphene Absorber with Lossless Phase Change Material Sb2S3

Abstract

Graphene absorbers have attracted lots of interest in recent years. They provide huge potential for applications such as photodetectors, modulators, and thermal emitters. In this letter, we design a high-quality (Q) factor resonant graphene absorber based on the phase change material Sb2S3. In the proposed structure, a refractive index grating is formed at the subwavelength scale due to the periodical distributions of amorphous and crystalline states, and the structure is intrinsically flat. The numerical simulation shows that nearly 100% absorption can be achieved at the wavelength of 1550 nm, and the Q factor is more than hundreds due to the loss-less value of Sb2S3 in the near-infrared region. The absorption spectra can be engineered by changing the crystallization fraction of the Sb2S3 as well as by varying the duty cycle of the grating, which can be employed not only to switch the resonant wavelength but also to achieve resonances with higher Q factors. This provides a promising method for realizing integrated graphene optoelectronic devices with the desired functionalities.

All‐Optical Switching of Structural Color with a Fabry–Pérot Cavity

“…Low-loss PCMs, including antimony trisulfide (Sb 2 S 3 ), antimony triselenide (Sb 2 Se 3 ), and antimony telluride (Sb 2 Te 3 ), have emerged for nanophotonic devices operating in the visible regime. [32][33][34] They offer many advantages, such as sustaining high Q-factor resonances for applications that require strong light-matter interactions, low optical losses in the visible spectrum, and ultrafast switching. [35][36][37][38][39][40][41] Moreover, their optical properties can be switched via external stimuli, such as electrical, optical, or thermal stimuli.…”