Room- and low-temperature voltage tunable electroluminescence from a single layer of silicon quantum dots in between two thin SiO2 layers

Room- and low-temperature electroluminescence (EL) in the visible range was observed from a single layer of silicon nanocrystals in between two thin SiO2 layers. The EL peak wavelength exhibited tunability from the red (∼800 nm) to the yellow (∼600 nm) depending on the excitation voltage. By decreasing the temperature while keeping the excitation voltage constant, an increase in EL intensity was observed together with a blueshift in EL peak position. This blueshift was much larger than that observed under optical excitation. Nonradiative Auger recombination, Coulomb charging effects, and/or the quantum-confined Stark effect are considered accountable for this behavior.