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; 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.

TechnischeUniversität柏林（TUB）和Paul-Drude-Institut（PDI）的共同目标在于基于多模式，狭窄的量子量子量表（Qcls and feentsery）的光谱仪，用于在Thz频率上进行高分辨率激光光谱仪的光谱仪，并构成了该光谱仪。线形状，以及杂质状态的松弛时间，尤其是同位素 - 纯GE和SI。浴缸组将开发一种新型THZ激光光谱仪，用于半导体中杂质转变的高分辨率光谱，尤其是在GE和SI中，频率在2.7至3.3 thz和5.0至5.7 thz的频率范围内。光谱仪基于QCL，该QCL是由PDI专门为此目的开发的。使用该光谱仪，浴缸组将研究GE和SI中的杂质转变，重点是捐助者和受体。目的是以最终的精度来确定杂质转变线的宽度和形状，即不通过光谱仪的设备函数限制光谱分辨率，因为使用傅立叶变换红外（FTIR）光谱仪通常是这种情况。 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激发电荷载体与声子的相互作用，并确定各种线扩展机制对整体线形状的贡献。特别是，我们的研究将包括对同位素富集的76GE和同位素纯28SI的研究，以了解同位素组成对线的宽度和形状的影响。这很有启发性，因为与Si相比，GE状态的晶格常数和声子密度不同。此外，我们还将使用泵探针技术对这些杂质转变进行时间分辨光谱，该技术可在自由电子激光器上获得。目的是确定国家的寿命，并将寿命与国家的线宽度进行比较。特别的重点将是对使用基于QCL的光谱仪的时间分辨泵探针技术和光谱分辨的抽象测量得出的寿命的完整分析。