Blue to red emission from as-deposited nc-silicon/silicon dioxide by hot wire chemical vapor deposition

Silicon thin films have been obtained with respect to the deposition time variation by using hot wire chemical vapor deposition. Silicon and related oxide particles both in crystalline phases embedded in amorphous silicon have been obtained by using tungsten as the catalyst material for the decomposition of source gases in the reaction chamber. Crystalline nature of the thin film has been shown using X-ray diffraction, transmission electron microscopy and scanning electron microcopy. X-ray diffraction patterns authenticate the presence of crystalline phases related to silicon and silicon dioxide in the matrix. Furthermore, transmission electron micrographs also revealed the presence of adjacent nature of silicon and silicon dioxide particles in the amorphous matrix. The as-deposited samples at low substrate temperature of about 200 °C have shown intense white photoluminescence spectra. No need of post-deposition annealing for light emission at room temperature has been demonstrated. This advantage of hot wire chemical vapor deposition technique could be considered for the mass production of optoelectronic devices in the future.