Electroluminescence of superatom-like Ge-core/Si-shell quantum dots by alternate field-effect-induced carrier injection

We have fabricated high-density superatom-like Si–Ge-based quantum dots (Si-QDs with Ge core) and studied their luminescence properties. Electroluminescence was observed from the Si-QDs with Ge core at room temperature in the near-infrared region by the application of square-wave pulsed bias of ±1 V at 500 kHz, which was attributed to radiative recombination between quantized states in the Ge core with deep potential well for holes caused by field-effect-induced alternate electron/hole injection from the substrate. The results lead to the development of Si-based light-emitting devices that are highly compatible with ultra-large-scale integration processing, which was found difficult to realize in silicon photonics.