The combined capabilities of both a nonplanar design and nonconventional carrier injection mechanisms are subject to recent scientific investigations to overcome the limitations of silicon metal oxide semiconductor field effect transistors. In this Letter, we present a multimode field effect transistors device using silicon nanowires that feature an axial n-type/intrinsic doping junction. A heterostructural device design is achieved by employing a self-aligned nickel-silicide source contact. The polymorph operation of the dual-gate device enabling the configuration of one p- and two n-type transistor modes is demonstrated. Not only the type but also the carrier injection mode can be altered by appropriate biasing of the two gate terminals or by inverting the drain bias. With a combined band-to-band and Schottky tunneling mechanism, in p-type mode a subthreshold swing as low as 143 mV/dec and an ON/OFF ratio of up to 104 is found. As the device operates in forward bias, a nonconventional tunneling transistor is realized, enabling an effective suppression of ambipolarity. Depending on the drain bias, two different n-type modes are distinguishable. The carrier injection is dominated by thermionic emission in forward bias with a maximum ON/OFF ratio of up to 107 whereas in reverse bias a Schottky tunneling mechanism dominates the carrier transport.

The combination of Moore's law and Dennard's scaling rules have constituted the fundamental guidelines for the silicon-based semiconductor industry for decades. Furthermore, the enormous growth of global data volume has pushed the demand for complex and densely packed devices. In recent years, it has become clear that wired interconnects impose increasingly severe speed and power limitations onto integrated circuits as scaling slows toward a halt. To overcome these limitations, there is a clear need for optical data processing. Despite significant progress in the development of silicon photonics, light sources remain challenging owing to the indirect bandgap of group IV materials. It is therefore highly desirable to develop new concepts for a silicon light source that meets efficiency and footprint requirements similar to their electronic counterparts. Here, we demonstrate an electrically driven and tunable silicon light source by matching the resonant modes of a silver nanocavity with the hot luminescence spectrum of an avalanching p−n junction. The cavity significantly enhances phononassisted recombination of hot carriers by tailoring the local density of states at the size-tunable resonance. Such tunable nanoscale emitter may be of great interest for short-reach communications, microdisplays or lab-on-chip applications.

Group-IV based light sources are one of the missing links towards fully CMOS compatible photonic circuits. Combining both silicon process compatibility and a pseudo-direct band gap, germanium is one of the most viable candidates. To overcome the limitation of the indirect band gap and turning germanium in an efficient light emitting material, the application of strain has been proven as a promising approach. So far the experimental verification of strain induced bandgap modifications were based on optical measurements and restricted to moderate strain levels. In this work, we demonstrate a methodology enabling to apply tunable tensile strain to intrinsic germanium 111 nanowires and simultaneously perform in situ optical as well as electrical characterization. Combining I/V measurements and μ-Raman spectroscopy at various strain levels, we determined a decrease of the resistivity by almost three orders of magnitude for strain levels of ∼5%. Thereof, we calculated the strain induced band gap narrowing in remarkable accordance to recently published simulation results for moderate strain levels up to 3.6%. Deviations for ultrahigh strain values are discussed with respect to surface reconfiguration and reduced charge carrier scattering time.

The realization of an efficient, silicon‐based light source with nanoscale dimensions may be the missing link to overcome the physical limitations of electrical signaling. Therefore, the generation of hot‐carriers to increase the transition possibilities within the band structure has shown promising results to cope with the inefficient light emission of indirect semiconductors. Here, we present the electroluminescent properties of NiSi2/silicon/NiSi2 nanowire heterostructures, operated at high electric fields. These hot carrier electroluminescent devices show highly reproducible, super‐ and sub‐bandgap emission of light, covering the visible spectrum and extending toward the near infrared regime. A pronounced peak, centered in the blue visible region at 2.6 eV is assigned to phonon‐assisted interband recombination of hot carriers. Spectral components at energies lower than 2.3 eV are linearly polarized along the nanowire axis and mainly attributed to intraband transitions.

Squeezing light out of silicon in an efficient way seems to be the missing link in prospective light‐based on‐chip communication. Therefore, the generation of hot carriers has shown promising results to cope with the inefficient light emission nature of indirect semiconductors. In the scope of their article, Sebastian Glassner et al. (pp. http://doi.wiley.com/10.1002/pssa.201600370) reported on the electroluminescent properties of NiSi2/silicon/ NiSi2 nanowire heterostructures. The heterostructures' ability to emit light thereby was confirmed to be a direct response to high electric fields applied, that initiate impact ionization in the submicron silicon nanowire segment. During avalanche operation of the devices, a high number of hot carriers is generated which increases transition probabilities within the silicon band structure and thus photon emission. The authors could show reproducible super‐and sub‐bandgap emission covering the visible spectrum and extending towards the near infrared regime. They further concluded that different mechanisms were responsible for the photon generation: Phonon‐assisted interband recombination is assingned to a spectral peak centered in the blue visible region – and intraband transitions dominate the lower energetic visible and near‐infrared regime.