We briefly explain different film deposition processes and analyze the visible photoluminescence mechanism from the obtained silicon nanoparticles. The deposited samples are SiOx and SiOxCy thin films fabricated by using catalytic chemical vapor deposition method (Cat-CVD). We used two different precursors as Monomethyl Silane (MMS) and Tetraethyl Orthosilicate (TEOS) for film deposition at relatively low substrate temperatures of 200 to 300 °C. In our earlier work, we have obtained the white emission from as-deposited samples by varying the catalyst temperature from 1700 to 1900 °C.
By using Scanning electron microscope (SEM) and transmission electron microscope (TEM), it was confirmed the formation of nano-crystals related to the composite of silicon oxide and silicon oxicarbide in the a-SiOx or a-SiOxCy matrix, respectively, without any need of extra annealing treatment. Various morphological and structural analysis has been performed using atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Some size distributions of particles were observed and its correlation with their bonding states to silicon, hydrogen and oxygen. Time resolved photoluminescence (TRPL) explain the possible emission mechanism. The decay time of < 2ns obtained from the thin films, remarks the possible contribution of quantum confinement effect (QCE) from the nano-crystals in SiOxCy matrix.
