基于人工微结构宽波段室温类石墨烯太赫兹探测器件及机理研究

Solid-state based terahertz detection technology is at the heart of applications in security, space optoelectronics. Graphene-like two-dimensional materials are highly sought-after as potential candidates for optoelectronic applications due to their unprecedented properties such as small electron specific heat, high mobility and high saturation velocity, but still confront with issues such as deep-subwavelength coupling, room temperature operation. In this investigation, we will focus on the realization of graphene and graphene-like group-5B transition metal-dichalcogenides-based terahertz detectors, clarifying the dynamics of two-dimensional plasmonic excitation, photo-thermoelectric process and the underlying mechanisms of terahertz detection, and build up the theoretical and experimental methodologies for designing two-dimensional material-based terahertz detectors. We seek to take full advantage the flexibility of two-dimensional materials in integration with artificial metamaterials, exploring the nonlinear interaction between electromagnetic wave and carriers, cavity enhanced light-matter interaction in strong correlation regime, and ultimately build up terahertz photovoltaic and photoconductive device in overcoming the difficulties in high-intensity integration with conventional antenna structures. Based on these results, we further exploit graphene/graphene-like heterostructures for functional compensation, utilizing the plasma effect to control the phase change of Mott insulator, superconductor and thermoelectric coupling, enabling the broadband room-temperature detection. Our investigation will improve people’s knowledge about the interaction between terahertz photon and electron in mesoscopic dimension, and open up the route to compact, flexible terahertz detection.

固态太赫兹探测技术是国家安全和空间光电技术等领域的核心，二维材料具有较小电子热电容和高迁移率等优异性能引起了国际上的关注，仍然面临着太赫兹的深亚波长光电耦合和室温工作的探测机理等关键科学问题。本项目申请将以石墨烯和强关联5B族硫系化合物为研究对象，通过理论模拟、器件制备和光电表征技术细致地分析类石墨烯探测器件的二维等离子体波、热电子微观动力学所呈现的宏观太赫兹探测效应，建立二维材料体系的室温太赫兹探测新方法，利用人工微结构光子操控与器件太赫兹探测相结合，探索电磁场与二维载流子非线性相互作用、光子结构腔—电子强关联调控作用，制备太赫兹光伏及光电导探测器结构，克服传统天线耦合大尺寸高密度集成的难题。进一步构建石墨烯/类石墨烯异质结构，探索等离子体调控器件Mott转变、超导转变、热电耦合，实现高效宽谱器件室温响应性能。课题的完成对微纳结构的太赫兹光子与电子相互作用和固态器件的应用有指导意义。

太赫兹波是位于微波和红外之间电磁辐射，在天文物理、空间防御、生命科学等多个领域具有重要的应用前景，而作为太赫兹技术核心的关键探测技术受材料、器件原理的限制面临着巨大的挑战，从而限制了太赫兹应用高技术的发展。二维材料具有较小的电子热电容和高迁移率特性有望为太赫兹技术瓶颈问题的解决带来新希望，然而光电耦合、室温太赫兹转换机理性问题的解决是形成革新性技术的关键。为此，围绕固态太赫兹探测在诸多领域的应用需求背景以及二维材料新光电研究为主线，本项目重点围绕石墨烯、5B族硫系化合物器件制备及材料表征、低维量子分析及器件模型研究、非线性效应与强关联体系的器件工艺研究为主线，面向解决低维材料光电耦合、热电子、关联相变等光电响应机理及器件光电增强调控等问题。通过研究，本项目建立了黑磷各项异性等离激元理论模型，实现了大面积CVD石墨烯器件工艺与热电子探测功能，获得了亚趋肤深度极限下的光场增强的热电子高灵敏探测。在此基础上，拓展研究基于拓扑半金属狄拉克电子体系的高性能、低功耗太赫兹直接光电转换，发现了新型位移电流、强关联相变驱动的高增益探测现象，形成了基于异质结-石墨烯、强关联量子拓扑的新型探测研究思路与集成方法，并实现了基于类石墨烯体系的高性能太赫兹成像功能。在本项目的支持下，获得了基于类石墨烯二维材料太赫兹探测的完善的理论与实验方法，在Science子刊Science Advances, Adv. Funct. Mater., Adv. Sci., Nano Energy, Small等国际顶级刊物发表论文13篇，申请专利5项，研究工作多次被MaterialsViewsChina, 太赫兹研发网，中国科学院网站等国内外重要学术媒体亮点报道，有望为新一代固态太赫兹探测与高性能集成奠定重要理论与实验基础。