高效单行载流子光电二极管太赫兹源研制

There has been an increasing interest in the terahertz (THz) sources based on photonics technologies. Due to the advantages such as continuous wave output, room temperature operation, broadband tenability, high power output, and compactness, etc, THz sources based on unitraveling carrier photodiodes (UTC-PDs) are highly practical. In this project, UTC-PDs for THz generation will be investigated. The main tasks are: Graded-bandgap absorption layer will be proposed to shorten the transit time of the electrons, and thus, to improve the bandwidth; The step-doping scheme in the collector layer will be optimized to better compensate the space charge, so the saturation current will be increased; Antennas and resonant matching circuits will be designed to improve the power conversion efficiency; and the material growth, high-speed packaging technics, as well as high efficient thermal packaging technics will also be studied. Through this project, broadband and high-output-power UTC-PDs for THz generation are expected, which could be used in applications such as high-speed THz wireless communication systems, THz spectroscopy systems, THz imaging systems, etc.

基于光子学技术的太赫兹（THz）辐射源是当前THz研究的热点之一。利用单行载流子光电二极管（UTC-PD）产生THz辐射具有连续输出、常温工作、宽带可调谐、输出功率大、体积适中等优点，实用价值很高，已受到科研界和工业界相关领域的广泛关注。本项目将开展高性能UTC-PD设计与制备方面的工作，具体包括研究器件内部载流子输运特性，对器件建模并进行性能模拟；提出具有梯度能带结构的吸收区，增强内建电场以加快电子移动速度，提升器件带宽；改进收集区阶梯掺杂方案，使杂质背景可以更有效的补偿空间电荷，从而提升饱和电流；设计发射天线与共振匹配电路，提高功率转换效率；研究器件材料生长的控制条件以及高速封装与高效散热技术。通过本项目的研究，预期实现宽带大功率的UTC-PD，并用于THz波的产生，为高速THz无线通信、THz频谱分析、THz成像等应用系统提供高性能的THz辐射源。

太赫兹（THz）辐射源和探测器是太赫兹技术应用的关键。利用单行载流子光电二极管（UTC-PD）产生THz辐射具有连续输出、常温工作、宽带可调谐、输出功率大等优点，受到科研界和工业界相关领域的广泛关注。本项目开展高性能UTC-PD设计与制备方面的工作，具体包括研究了器件内部载流子输运特性，对器件建模并进行性能模拟，给出了功率特性、带宽和饱和度性能提升的方法；提出了具有梯度能带结构的吸收区，增强内建电场以加快电子移动速度，提升器件带宽；改进收集区阶梯掺杂方案，使杂质背景可以更有效的补偿空间电荷，从而提升饱和电流；基于分子束外延技术进行了器件材料生长，自主开发了器件工艺与封装测试技术，完成了器件研制。经过测试，器件可以在室温下工作，频率连续可调谐，工作频率大于0.2THz，输出功率达到1.05mW。