Electrical characterization of Ge0.81Sn0.19 nanowires has been performed revealing high electrical conductivity and semiconductor behaviour when cooled to 10 K. The impact on slightly elevated temperatures on the device stability of this metastable material is described.

The thermoelectric properties of a nanoscale germanium segment connected by aluminium nanowires are studied using scanning thermal microscopy.

In the quest to push the contemporary scientific boundaries in nanoelectronics, Ge is considered a key building block extending device performances, delivering enhanced functionalities. In this work, a quasi‐1D monocrystalline and monolithic Al–Ge–Al nanowire heterostructure are embedded into a novel field‐effect transistor architecture capable of combining Ge based electronics with an electrostatically tunable negative differential resistance (NDR) distinctly observable at room temperature. In this regard, a detailed study of the key metrics of NDR in Ge is presented. Most notably, a highly efficient and low‐footprint platform is demonstrated, paving the way for potential applications such as fast switching multi‐valued logic devices, static memory cells, or high‐frequency oscillators, all implemented in one fully complementary metal–oxide–semiconductor compatible Al‐Ge based device platform.

Recent advances in guiding and localizing light at the nanoscale exposed the enormous potential of ultrascaled plasmonic devices. In this context, the decay of surface plasmons to hot carriers triggers a variety of applications in boosting the efficiency of energy-harvesting, photocatalysis, and photodetection. However, a detailed understanding of plasmonic hot carrier generation and, particularly, the transfer at metal–semiconductor interfaces is still elusive. In this paper, we introduce a monolithic metal–semiconductor (Al–Ge) heterostructure device, providing a platform to examine surface plasmon decay and hot electron transfer at an atomically sharp Schottky nanojunction. The gated metal–semiconductor heterojunction device features electrostatic control of the Schottky barrier height at the Al–Ge interface, enabling hot electron filtering. The ability of momentum matching and to control the energy distribution of plasmon-driven hot electron injection is demonstrated by controlling the interband electron transfer in Ge, leading to negative differential resistance.

Surface plasmon polaritons have rapidly established themselves as a promising concept for molecular sensing, near-field nanoimaging, and transmission lines for emerging integrated ultracompact photonic circuits. In this letter, we demonstrate a highly compact surface plasmon polariton detector based on an axial metal-semiconductor-metal nanowire heterostructure device. Here, an in-coupled surface plasmon polariton propagates along an aluminum nanowire waveguide joined to a high index germanium segment, which effectively acts as a photoconductor at low bias. Based on this system, we experimentally verify surface plasmon propagation along monocrystalline Al nanowires as thin as 40 nm in diameters. Furthermore, the monolithic integration of plasmon generation, guiding, and detection enables us to examine the bending losses of kinked waveguides. These systematic investigations of ultrathin monocrystalline Al nanowires represent a general platform for the evaluation of nanoscale metal based waveguides for transmission lines of next generation high-speed ultracompact on-chip photonic circuits.