Electroluminescence from NiSi2/Si/NiSi2 nanowire heterostructures operated at high electric fields (Phys. Status Solidi A 11∕2016)

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. 2895-2900) 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.