Armand Pilon F T, Lyasota A, Niquet Y-M, Reboud V, Calvo V, Pauc N, Widiez J, Bonzon C, Hartmann J M, Chelnokov A, Faist J, Sigg H
Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232, Villigen, Switzerland.
Institute for Quantum Electronics, ETH Zürich, 8093, Zürich, Switzerland.
Nat Commun. 2019 Jun 20;10(1):2724. doi: 10.1038/s41467-019-10655-6.
Germanium has long been regarded as a promising laser material for silicon based opto-electronics. It is CMOS-compatible and has a favourable band structure, which can be tuned by strain or alloying with Sn to become direct, as it was found to be required for interband semiconductor lasers. Here, we report lasing in the mid-infrared region (from λ = 3.20 μm up to λ = 3.66 μm) in tensile strained Ge microbridges uniaxially loaded above 5.4% up to 5.9% upon optical pumping, with a differential quantum efficiency close to 100% with a lower bound of 50% and a maximal operating temperature of 100 K. We also demonstrate the effect of a non-equilibrium electron distribution in k-space which reveals the importance of directness for lasing. With these achievements the strained Ge approach is shown to compare well to GeSn, in particular in terms of efficiency.
长期以来，锗一直被视为硅基光电子学中一种很有前景的激光材料。它与CMOS兼容，具有良好的能带结构，这种结构可通过应变或与锡合金化来调整为直接带隙结构，正如人们发现带间半导体激光器所需要的那样。在此，我们报告了在拉伸应变的锗微桥中实现了中红外区域（波长从λ = 3.20μm至λ = 3.66μm）的激光发射。这些微桥在光泵浦下，单轴拉伸应变超过5.4%直至5.9%，微分量子效率接近100%，下限为50%，最高工作温度为100K。我们还展示了k空间中非平衡电子分布的影响，这揭示了直接带隙结构对激光发射的重要性。通过这些成果表明，应变锗方法与锗锡相比具有优势，特别是在效率方面。
