Qin Yaling, Liu Min, Teng Hanchao, Chen Na, Wu Chenchen, Jiang Chengyu, Xue Zhuoxin, Zhu Hualong, Gui Jiayi, Liu Xiang, Xiao Yuchuan, Hu Hai
School of Materials Science and Engineering, Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450001, China.
CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
Nanoscale. 2024 Nov 13;16(44):20522-20531. doi: 10.1039/d4nr00942h.
Graphene plasmons exhibit significant potential across diverse fields, including optoelectronics, metamaterials, and biosensing. However, the exposure of all surface atoms in graphene makes it susceptible to surrounding interference, including losses stemming from charged impurity scattering, the dielectric environment, and the substrate roughness. Thus, designing a dielectric environment with a long lifetime and tunability is essential. In this study, we created a van der Waals (vdW) heterostructure with graphene nanoribbons and mica nano-films. Through Fourier-transform infrared spectroscopy, we identified hybrid modes resulting from the interaction between graphene plasmons and mica phonons. By doping and manipulating the structure of graphene, we achieved control over the phonon-plasmon ratio, thereby influencing the characteristics of these modes. Phonon-dominated modes exhibited stable resonant frequencies, whereas plasmon-dominated modes demonstrated continuous tuning from 1140 to 1360 cm in resonance frequency, accompanied by an increase in extinction intensity from 0.1% to 1.2%. Multiple phonon couplings limited frequency modulation, yielding stable resonances unaffected by the gate voltage. Mica substrates offer atomic level flatness, long phonon lifetimes, and dielectric functionality, enabling hybrid modes with high confinement, extended lifetimes (up to 1.9 picoseconds), and a broad frequency range (from 750 cm to 1450 cm). These properties make our graphene and mica heterostructure promising for applications in chemical sensing and integrated photonic devices.
石墨烯等离激元在包括光电子学、超材料和生物传感在内的多个领域展现出巨大潜力。然而，石墨烯中所有表面原子的暴露使其易受周围环境干扰，包括带电杂质散射、介电环境和衬底粗糙度导致的损耗。因此，设计具有长寿命和可调性的介电环境至关重要。在本研究中，我们创建了一种由石墨烯纳米带和云母纳米薄膜组成的范德华（vdW）异质结构。通过傅里叶变换红外光谱，我们识别出了由石墨烯等离激元和云母声子相互作用产生的混合模式。通过对石墨烯结构进行掺杂和调控，我们实现了对声子 - 等离激元比率的控制，从而影响这些模式的特性。以声子为主的模式表现出稳定的共振频率，而以等离激元为主的模式在共振频率上呈现出从1140至1360厘米连续可调，同时消光强度从0.1%增加到1.2%。多个声子耦合限制了频率调制，产生不受栅极电压影响的稳定共振。云母衬底具有原子级平整度、长声子寿命和介电功能，能够实现具有高限制、延长寿命（长达1.9皮秒）和宽频率范围（从750厘米至1450厘米）的混合模式。这些特性使我们的石墨烯 - 云母异质结构在化学传感和集成光子器件应用方面颇具前景。
