Meng Qi, Chen Xingqiao, Xu Wei, Zhu Zhihong, Qin Shiqiao, Zhang Jianfa, Yuan Xiaodong
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China.
Hunan Provincial Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha 410073, China.
Nanomaterials (Basel). 2021 Oct 24;11(11):2820. doi: 10.3390/nano11112820.
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 SbS. 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 SbS in the near-infrared region. The absorption spectra can be engineered by changing the crystallization fraction of the SbS 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.
近年来，石墨烯吸收体引起了广泛关注。它们在诸如光电探测器、调制器和热发射器等应用中具有巨大潜力。在本信函中，我们基于相变材料Sb2S3设计了一种高品质（Q）因子共振石墨烯吸收体。在所提出的结构中，由于非晶态和晶态的周期性分布，在亚波长尺度上形成了折射率光栅，并且该结构本质上是平坦的。数值模拟表明，在1550nm波长处可实现近100%的吸收，并且由于Sb2S3在近红外区域的无损值，Q因子超过数百。通过改变Sb2S3的结晶分数以及改变光栅的占空比，可以对吸收光谱进行调控，这不仅可以用于切换共振波长，还可以实现具有更高Q因子的共振。这为实现具有所需功能的集成石墨烯光电器件提供了一种有前景的方法。
