Hydrogen Passivation of Luminescence-Quenching Defects in Si Nanocrystals

초록

Si nanocrystals embedded in silicon-dioxide films are exposed to either atomic or molecular hydrogen at 300 degrees C. Both exposures are shown to result in an increase in the photoluminescence (PL) intensity with increasing exposure time, followed by saturation. The saturation intensity strongly depends on the hydrogen type, showing a larger PL intensity for atomic hydrogen than for molecular hydrogen. Furthermore, the thermal stability of the PL intensity induced by atomic hydrogen exposure is shown to be less than that induced by molecular hydrogen exposure. These results demonstrate the presence of at least two different luminescence-quenching defects at the Si nanocrystal/SiO2 interface: one that is passivated by atomic hydrogen and one that is only passivated by molecular hydrogen.

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