Electroluminescence of single-dot nano-LEDs—optical spectroscopy of an electrically tunable few-electron/hole system

In this contribution we present a new device concept for nano-structured LEDs that allows for optical and electrical measurements on single quantum dots. Our LEDs have an active region smaller than 1 μm2 and are fabricated by using focused ion beam (FIB) doping and subsequent MBE-overgrowth. We present promising results from electroluminescence measurements, which confirm the single-dot character of our devices. The spectra consist of sharp emission lines, which can be assigned to exciton recombination from a single quantum dot. Operated under pulsed conditions our nano-LED should be particularly suitable for an electrically driven single-photon source.