Abstract
During last few years much effort has been made on the research of nanostructures novel, especially Si-based luminescent nanostructures due to their optical properties. However, the luminescence mechanisms for most of these luminescent materials are not clear and definitive till now. The present work involves the fabrication of oxygen-containing Si nanoparticles (OCSNs) by a thermal evaporation technique and measurement of photoluminescence (PL). The possible mechanism responsible for the PL is discussed.The SiOx nanoparticles were prepared in a mixed atmosphere of argon and oxygen. The effect of Si weight on the formation of the nanocrystals and the PL properties is studied in this thesis. The SiOx nanoparticles prepared with lower oxygen content exhibit lower PL intensity, while a strong blue-green PL is observed from those prepared with higher oxygen contents. It is interesting to note that there is a critical oxygen-content in the SiOx nanoparticles emits PL light varying from blue-white to orange. The mechanism of blue-light emission from SiOx nanoparticles is also discussed. In another experiment, it is found that the PL properties have been changed after depositing the SiOx nanoparticleson the Si substrate. The structure and PL behavior of these SiOx films are also discussed on the basis of low angle XRD and FESEM analyes.The last part of this thesis is focused on the low-temperature PL behavior of isolated SiOx nanoparticles and SiOx films. The PL intensity is increased after the low temperature PL test. The intensity transition temperatures for SiOx nanoparticles and SiOx films have also been measured. The low temperature PL behaviors of the SiOx nanoparticles and SiOx are discussed in terms of the changes of the SiOx nanostructures. After low temperature PL test, it is interesting to note that the structures of SiOx films have been changed. This change in structure may be responsible for higher PL intensity.Key words：SiOx nanoparticles, SiOx films, PL, XRD, TEM, FESEM, Low-temperature PL