Strong quantum confinement and coulomb blockade effects in Ge quantum dots/SiO2 system

We reported experimental observations of strong quantum confinement and coulomb blockade effects in germanium (Ge) quantum dots (QDs)/SiO₂ system. With a CMOS-compatible method, nanometer-scale Ge QDs (less than 10 nm) could be controllably formed for novel optoelectronic device applications such as single-electron transistors (SETs) as well as light emitter or detectors. Distinguishable photoemission from Ge QDs and relevant blueshifts of the emission peaks are observed from room-temperature cathodoluminescence spectra. Ge QD SETs were also experimentally realized with a large single-electron addition energy and an energy level separation of 125 meV and 50 meV, respectively.