Han Zexiang, Wang Fei, Sun Juehan, Wang Xiaoli, Tang Zhiyong
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Adv Mater. 2023 Jan;35(3):e2206141. doi: 10.1002/adma.202206141. Epub 2022 Nov 29.
Artificial chiral nanostructures have been subjected to extensive research for their unique chiroptical activities. Planarized chiral films of ultrathin thicknesses are in particular demand for easy on-chip integration and improved energy efficiency as polarization-sensitive metadevices. Recently, controlled twisted stacking of two or more layers of nanomaterials, such as 2D van der Waals materials, ultrathin films, or traditional metasurfaces, at an angle has emerged as a general strategy to introduce optical chirality into achiral solid-state systems. This method endows new degrees of freedom, e.g., the interlayer twist angle, to flexibly engineer and tune the chiroptical responses without having to change the material or the design, thus greatly facilitating the development of multifunctional metamaterials. In this review, recent exciting progress in planar chiral metasurfaces are summarized and discussed from the viewpoints of building blocks, fabrication methods, as well as circular dichroism and modulation thereof in twisted stacked nanostructures. The review further highlights the ever-growing portfolio of applications of these chiral metasurfaces, including polarization conversion, information encryption, chiral sensing, and as an engineering platform for hybrid metadevices. Finally, forward-looking prospects are provided.
人工手性纳米结构因其独特的手性光学活性而受到广泛研究。作为偏振敏感的超材料器件，超薄平面手性薄膜因其易于片上集成和提高能量效率而备受关注。最近，将两层或多层纳米材料（如二维范德华材料、超薄膜或传统超表面）以一定角度进行可控扭曲堆叠，已成为一种将光学手性引入非手性固态系统的通用策略。这种方法赋予了新的自由度，例如层间扭曲角，从而能够灵活地设计和调节手性光学响应，而无需改变材料或设计，极大地促进了多功能超材料的发展。在这篇综述中，我们从构建单元、制备方法以及扭曲堆叠纳米结构中的圆二色性及其调制等方面，总结并讨论了平面手性超表面的最新研究进展。该综述进一步强调了这些手性超表面不断增长的应用组合，包括偏振转换、信息加密、手性传感以及作为混合超材料器件的工程平台。最后，我们给出了前瞻性展望。
