Structural and optical investigation of silicon-based nanocrystals

The aim of this study is the production of nano-sized materials managed to attract the attention of many researchers in recent technological applications. For this aim, thin films have been grown using by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique. After that, these films have been subjected to annealing for the formation of nanocrystals in the matrix. Ge nanocrystals formed by annealing in silicon oxide (SiO2) film were investigated with High Resolution Transmission Electron Microscopy (HRTEM), Raman, photoluminescence (PL) and Fourier Transform Infrared (FTIR) spectroscopic techniques. SiO2 thin films containing Ge nanocrystals have been grown by using various gas flow rates of GeH4, SiH4 and N2O gases in the plasma chamber. As a result of annealing it were seen Ge nanocrystals formations for various gas flow rates by Raman and FTIR Spectroscopy. The obtained results show that nanocrystal size depend on gas flow rate, clearly. Morever, optical properties have been investigated for these nanocrystals by using Photoluminescence. The results presented in this thesis have been showed good agreement with literature.