High-resolution terahertz semiconductor spectroscopy using quantum-cascade lasers: Spectros-copy of impurity transitions in Ge and Si

使用量子级联激光器的高分辨率太赫兹半导体光谱：Ge 和 Si 中杂质跃迁的光谱复制

• 批准号: 269855598
• 负责人: Professor Dr. Heinz-Wilhelm Hübers
• 金额: --
• 依托单位: Institut für Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/269855598?language=en
• 关键词: resolution; terahertz; semiconductor; spectroscopy; using

The common goal of the groups at the Technische Universität Berlin (TUB) and the Paul-Drude-Institut (PDI) consists in the demonstration of a spectrometer for high-resolution laser spectroscopy of semiconductors at THz frequencies based on multi-mode, narrow-line-width quantum-cascade lasers (QCLs) combined with a grating spectrometer as well as the investigation of the line width, line shape, and the relaxation time of impurity states in particular in isotope-pure Ge and Si. The TUB group will develop a novel THz laser spectrometer for high-resolution spectroscopy of impurity transitions in semiconductors, in particular in Ge and Si, in the frequency ranges from 2.7 to 3.3 THz and 5.0 to 5.7 THz. The spectrometer is based on QCLs, which are specifically developed for this purpose by the PDI. With this spectrometer, the TUB group will investigate impurity transitions in Ge and Si with the focus on shallow donors and acceptors. The goal is to determine the width and shape of the line of the impurity transitions with ultimate accuracy, i.e. without the limitation of the spectral resolution by the apparatus function of the spectrometer as it is usually the case when a Fourier transform infrared (FTIR) spectrometer is used. The QCL spectrometer will have an about one thousand times larger spectral resolution than high-resolution FTIR spectrometers. This will enable us to study the interaction of excited charge carriers with phonons very precisely and to determine the contributions of various line broadening mechanisms to the overall line shape. In particular, our investigations will include studies of isotopically enriched 76Ge and isotopically pure 28Si in order to understand the influence of the isotopic composition on the width and shape of the line. This is instructive, because of the different lattice constants and phonon density of states of Ge as compared to Si. The influence of external perturbations such as a magnetic field or a compressive force on the transition frequencies as well as the width and the shape of the line will also be investigated. In addition, we will perform time-resolved spectroscopy of these impurity transitions using the pump-probe technique, which is available at free-electron lasers. The goal is to determine the life-time of the states and to compare the lifetime with the line width of the states. A special focus will be the complementary analysis of the lifetimes derived from time-resolved pump-probe techniques and spectrally resolved absorption measurements with the QCL-based spectrometer.

柏林工业大学（TUB）和Paul-Drude-Institut（PDI）的共同目标是演示一种光谱仪，用于太赫兹频率下半导体的高分辨率激光光谱学，该光谱仪基于多模窄线宽量子级联激光器（QCL）与光栅光谱仪相结合，以及对线宽、线形、以及杂质态的弛豫时间，特别是在同位素纯Ge和Si中。TUB小组将开发一种新型的THz激光光谱仪，用于半导体中杂质跃迁的高分辨率光谱学，特别是Ge和Si，频率范围为2.7至3.3 THz和5.0至5.7 THz。光谱仪基于PDI为此专门开发的QCL。利用这台光谱仪，TUB小组将研究Ge和Si中的杂质跃迁，重点是浅施主和受主。目标是以最终精度确定杂质跃迁线的宽度和形状，即，不受光谱仪的装置功能对光谱分辨率的限制，因为通常使用傅里叶变换红外（FTIR）光谱仪时就是这种情况。QCL光谱仪的光谱分辨率将比高分辨率FTIR光谱仪大约一千倍。这将使我们能够非常精确地研究受激载流子与声子的相互作用，并确定各种谱线展宽机制对整个谱线形状的贡献。特别是，我们的研究将包括同位素富集的76 Ge和同位素纯的28 Si的研究，以了解同位素组成对线的宽度和形状的影响。这是有益的，因为与Si相比，Ge的晶格常数和声子态密度不同。外部扰动，如磁场或压缩力的过渡频率，以及线的宽度和形状的影响也将被调查。此外，我们将使用泵浦-探测技术对这些杂质跃迁进行时间分辨光谱分析，该技术在自由电子激光器中可用。目标是确定状态的寿命，并将寿命与状态的线宽进行比较。一个特别的重点将是来自时间分辨泵浦探测技术和光谱分辨吸收测量与QCL为基础的光谱仪的寿命的互补分析。

项目成果

Terahertz gas spectroscopy through self-mixing in a quantum-cascade laser

通过量子级联激光器中的自混合进行太赫兹气体光谱

• DOI: 10.1063/1.4967435
• 发表时间: 2016
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: T. Hagelschuer;M. Wienold;H. Richter;L. Schrottke;K. Biermann;H. T. Grahn;H.-W. Hübers
• 通讯作者: H.-W. Hübers

High-Resolution terahertz gas-phase spectroscopy based on external optical feedback in a quantum cascade laser

基于量子级联激光器外部光反馈的高分辨率太赫兹气相光谱

• DOI: 10.1109/irmmw-thz.2017.8067144
• 发表时间: 2017
• 期刊: 2017 42nd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
• 作者: T. Hagelschuer;M. Wienold;H. Richter;N. Rothbart;H.-W. Hübers
• 通讯作者: H.-W. Hübers

Lamb dip spectroscopy with a terahertz quantum-cascade laser

使用太赫兹量子级联激光器进行兰姆浸光谱

• DOI: 10.1109/irmmw-thz.2017.8067125
• 发表时间: 2017
• 期刊: 2017 42nd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
• 作者: M. Wienold;T. Alam;L. Schrottke;H. T. Grahn;H.-W. Hübers
• 通讯作者: H.-W. Hübers