Synthesis of silicon nanocrystals in aluminum-doped SiO2 film by laser ablation method

The effects of aluminum (Al-) doping in SiO2 film containing silicon-nanocrystal (nc-Si) dots were investigated by photoluminescence (PL) and electron spin resonance (ESR) measurements. The observed PL peak center showed a blueshift due to reduction of size of nc-Si dots as a result of the Al doping followed by annealing within a range of 600–800 °C. For the samples annealed at 1000 °C, the PL intensity showed increases with increasing concentration of Al atoms in the SiO2. The ESR results obtained from all the samples, however, revealed that the density of defects causing the PL quenching did not show decrease by the Al doping. Therefore, the enhancement of the PL intensity by the Al doping seemed to be caused probably by the increase in the density of nc-Si dots.