太赫兹波与中远红外光探测及调制用的高性能二维晶体极化激元序构材料研究

探测和主动调制器件是太赫兹与中远红外谱段科技及应用的核心，也是现阶段的难点。材料是实现器件的基础。传统窄带隙半导体室温暗电流高、电磁响应弱、吸收波段有限、物性调节响应慢、高质量晶体制备难，制约了室温工作高灵敏快速响应的探测和主动调制器件的发展。人工微结构、能带工程结构及低维材料有望解决上述问题，但仍存在电磁吸收弱、量子产率低及阵列集成器件制作复杂等共性问题。具有极化激元效应的二维晶体在高性能电磁场探测和调制器件应用上展示了巨大的潜力，但相关研究仍处于起步阶段。本项目以实现工作频率在1.0−30THz的高效探测和调制材料为目标，研究二维晶体极化激元功能结构中电磁场耦合与局域的新效应和新机制，并通过将功能基元与空间序构结合，利用基元的极化激元叠加和协同耦合效应增强材料的电磁响应，实现材料对电磁波的窄带/宽谱、波长选择及偏振选择响应，获得太赫兹与中远红外谱段光及电磁波探测与调制高效高性能材料。

The ever-growing demand for wireless communications leads to an urgent need for high performance optical detectors and modulators with working frequencies spanning from terahertz to mid infrared (MIR) regions. However, lacking of natural materials with high electromagnetic responses at such frequency range is recognized as a bottleneck. Traditional narrow bandgap semiconductors suffer from several drawbacks such as complex fabrication procedures, high dark current, narrow operating frequency range, long response time and weak electromagnetic responses, which limit the development of room-temperature detectors and modulators with high sensitivity and fast response. With the recent advances in artificial nanomaterials and energy-band-engineering materials, two-dimensional (2D) materials with exceptional polaritonic resonances offer a rich platform to overcome such problems, yet low quantum yield, weak electromagnetic absorption and fabrication difficulty remaining to be solved. In this proposal, we attempt to design high performing detection and modulation materials with superior properties such as narrow/broad band working spectral range, high frequency-selectivity, polarization-resolved responses and room temperature operation. Functional building blocks is strategically designed using 2D crystal nanostructures with novel polaritonic effects. By taking advantage of their polaritonic coupling effects and superimposing effects, such functional building blocks are judicious arranged to construct ordered structure materials with unprecedented electromagnetic response ability. We expect this project will pave the way for high-performance materials with operation frequency ranging from 1 to 30 THz.