CORRELATION OF RAMAN AND PHOTOLUMINESCENCE SPECTRA OF Al2O3 CAPPED SILICON NANOPARTICLES GROWN BY REACTIVE PULSED LASER DEPOSITION

Synthesis and observation of a correlation between the Raman spectra and photoluminescence (PL) of silicon nanoparticles (Si-nps) embedded in Al2O3 matrix grown by reactive pulsed laser deposition in oxygen atmosphere are reported. We observed a strong dependence of the band gap, photoluminescence intensity and Raman spectra of Si-nps on the ambient oxygen gas pressure during the deposition. It appears that with increasing oxygen pressure the enhanced oxidation of silicon into SiOx, which surrounds the Si-nps is responsible for the increase in the band gap, enhancement in the PL intensity and suppression of the Si related Raman mode observed in these studies.