We present a magneto-optical study of the carrier dynamics in compressively strained ${\mathrm{Ge}}_{1-x}{\mathrm{Sn}}_x$ films with $\mathrm{Sn}$ content up to 10% epitaxially grown on $\mathrm{Ge}$ on $\mathrm{Si}$(001) virtual substrates. We leverage the Hanle effect under steady-state excitation to study the spin-dependent optical transitions in the presence of an external magnetic field. This allows us to obtain direct access to the dynamics of the optically induced carrier population. Our approach reveals that at cryogenic temperatures the effective lifetime of the photogenerated carriers in coherent ${\mathrm{Ge}}_{1-x}{\mathrm{Sn}}_x$ is on the subnanosecond timescale. Supported by a model estimate of the radiative lifetime, our measurements indicate that carrier recombination is dominated by nonradiative processes. Our results thus provide central information to improve the fundamental understanding of carrier kinetics in this advanced direct-band-gap group-IV-material system. Such knowledge can be a stepping stone in the quest for the implementation of ${\mathrm{Ge}}_{1-x}{\mathrm{Sn}}_x$-based functional devices.

中文翻译：

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Ge1-xSnx / GeHetero结构中载流子寿命的连续波磁光确定

我们提出了在压缩应变中载流子动力学的磁光研究。 ${\mathrm{通用电器}}_{\mathrm{1个}-X}{锡}_X$ 电影与 $锡$ 外延生长的金属含量高达10％ $\mathrm{通用电器}$ 上 $硅$（001）虚拟衬底。我们利用稳态激发下的Hanle效应研究存在外部磁场时自旋相关的光学跃迁。这使我们能够直接访问光诱导载流子种群的动力学。我们的方法表明，在低温下，相干光生载流子的有效寿命${\mathrm{通用电器}}_{\mathrm{1个}-X}{锡}_X$是亚纳秒级的时间刻度。在辐射寿命的模型估计的支持下，我们的测量结果表明，载流子复合受非辐射过程的支配。因此，我们的结果提供了中心信息，以改善这种先进的直接带隙-IV族材料体系中对载流子动力学的基本理解。此类知识可以成为寻求实施的踏脚石。${\mathrm{通用电器}}_{\mathrm{1个}-X}{锡}_X$基于功能的设备。