Photoluminescence intensity modulation by charge carrier injection in silicon nanocrystals at room temperature

Abstract

Hysteretic intensity modulation of the photoluminescence (PL) of silicon nanocrystals (Si-NCs) embedded in silicon oxide (SiO2) is observed in metal-oxide-semiconductor (MOS) structures at room temperature during gate voltage sweeps of ±3 V. This PL intensity modulation is correlated with simultaneous current density measurements in the different operating regimes of these MOS devices. In particular, PL intensity enhancement is shown to result from electron injection into the oxide. The different mobilities of the charge carriers in SiO2 and the competing effects of charge trapping in the Si-NC and the surrounding oxide defects are used to explain the observed PL modulation.