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 (similar to 800 nm) to the yellow (similar to 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. (C) 2000 American Institute of Physics. [S0003-6951(00)02336-6].