表面等离基元金属纳米结构光致电势效应及其传感器应用研究

Surface Plasmon Polariton (SPP) based optical sensors have attracted extensive research interest in recent years. As a real-time, lable-free and efficient optical sensing technique, SPP sensors have been applied for the detection of a variety of chemical and biological analyte. However, because of their bulky, complex and expensive optical mounting and detecting systems, the most common commercial SPP sensors with Kretschmann configuration are currently being challenged by the growing requirements for ultra-high sensitive, multi-channel and multi-pixel sensing. The SPP induced surface photovoltage (SPP-SPV) in metal nanostructures is a newly developed photoelectric conversion mechanism, which holds great potential to realize the electrical readout sensing and significantly simplify the configuration of the sensing instrumentations. In this project, we focus on the SPP-SPV effects of the metallic nanostructures and their application in sensing. By incorporating the near-field scanning optoelectric probe, the spatially and spectrally resolved mapping of the SPP-SPV in metallic nanostructures will be studied. We will employ the theoretical means to reveal the macroscopic thermodynamic mechanisms of the observed SPP-SPV effects in the metal nanostructures. Form energy point of view, we will adopt the perfect light absorber designs to obtain efficient light absorption and thus the gain in SPP-SPV. Meanwhile, we will also resort to the perfect light absorbers to enhance the light-matter-structure interaction in the nanostructures. Therefore, high refractometric sensitivity can be obtained in our sensing structures. We will then fabricate the electric readout SPP-SPV sensor and finally demonstrate its high abilities in sensing.

近年来，基于表面等离基元（SPP）的光学传感器得到了广泛研究。作为实时、无标记的高效光学检测手段，SPP传感器已应用于一系列化学、生物学分析物的检测与研究。然而，由于其庞大、复杂且昂贵的光学对准与检测系统，商用SPP传感器正面临着高灵敏、多通道、芯片化以及多像素成像检测的巨大挑战。金属纳米结构的表面等离基元诱导光电压（SPP-SPV）作为一种全新的光电转换机制，为SPP传感器的电信号读取带来契机，有望降低SPP传感设备及检测复杂性。本项目将围绕SPP-SPV效应及其传感应用，采用近场扫描光电探针获取空间与频域分辨的电势信息，结合理论手段揭示其微观热动力学机制，从能量摄入角度探索采用完美吸收结构获取SPP-SPV光电转换增益。同时，借助完美吸收结构的光场局域特性促进光-物质-结构强关联耦合，获得金属纳米结构的探测灵敏度增益。研制基于SPP-SPV电压信号读出的原型传感器并展现其高效传感性能。

纳米等离激元传感器由于可在小尺度上实现非标记、实时和超灵敏的检测，其在坏境检测、化学和医药诊断等领域上的应用取得了巨大的进步。然而，几乎所有主流光学传感器仍高度依赖昂贵和庞大的光谱或成像设备及方法，限制了其在未来即时诊断上的关键应用。在本项目中我们提出并研制了一种光电集成片上系统，在无需光谱、外设探测和光学组件及设备的基础上实现直接电读出的光学传感。项目所研制的超紧凑光学传感器通过有机集成表面等离激元传感和光电信号转换两个方面来实现片上电学读出的功能。利用金属-硅基体系上的完美吸收/高品质因子共振结构与新颖的表面等离激元光电转换机制，我们实现了1e-6 RIU的传感灵敏度，并具备700-1700nm的宽带工作特点。项目所取得的研究成果对发展硅基兼容的超敏光电探测/传感系统有着显著的科学意义，在临床检测、红外探测和片上光谱等重点方向上具备较高的应用潜质。