在电子、信息与生命等领域蕴藏着巨大应用前景的太赫兹波（THz）的发展，受到缺少高性能固态THz探测器的严重限制。GaAs/AlGaAs THz量子阱探测器（QWP）是可能的解决方案，缺点是响应度与波长可调范围离实际应用尚有差距。然而，基于量子阱子带能级跃迁的传统探测机制决定了难以对上述缺点进行显著改进。为此，本项目提出了一种新型GaAs/AlGaAs THz QWP概念，即先利用势阱层中朗道能级的量子化效应，通过磁场操控朗道能级与势垒层中类氢施主基态能级的共振，使电子发生自势阱层向势垒层的转移；再利用处于类氢施主基态能级上电子的光热电离效应实现对入射THz辐射的响应。在保持传统THz QWP优点的同时，从原理上实现高响应度与宽波长可调的THz探测。本项目将详细研究新型器件中电子在共振能级间转移的散射机制、器件工作原理、载流子输运及相应的磁场调控技术。本研究也为THz探测的基础理论做出贡献。

The development of terahertz (THz) electromagnetic waves which have potential applications in many fields such as electronics, information and medical diagnosis is limited by the lack of high performance solid-state THz detectors. The GaAs/AlGaAs THz quantum well photodetector (QWP) is one strong candidate except its low responsivity and narrow wavelength-tunability, which could be hardly overcome in the traditional detection mechanism inherently based on intersubband transition in quantum wells. In this project, we propose a novel GaAs/AlGaAs THz QWP concept which firstly exploits the quantization of Landau level in well layers to control their resonant with the ground state of hydrogenic donor in barrier layers leading to the electron transfer between well and barrier layers, and subsequently exploits the photothermal ionization of electrons in the ground state of hydrogenic donor to respond to incident THz irradiations. In this research, we will investigate on the electron scattering mechanism between resonant states, novel THz detection mechanism, unusual carrier transport phenomenon, and try to develop corresponding modulation technologies by magnetic field. We aim at realization of intrinsically high responsivity and wide wavelength-tunability GaAs/AlGaAs THz QWP. Meanwhile, this research will contribute to the fundamental physics of THz detections.