Luminescent silicon oxycarbide thin films obtained with monomethyl-silane by hot-wire chemical vapor deposition

Abstract

The use of silicon-based materials can represent enormous advantages to develop optoelectronic devices. The preparation of luminescent silicon oxycarbide thin films deposited by the hot-wire CVD technique using monomethyl-silane as single and safer source of silicon and carbon atoms is here reported. The conditions for deposition that allow obtaining an intense emission on these thin films in a wide region of the visible spectrum at low deposition temperature without further thermal annealing are presented. When the oxygen flow rate was increased, a transition from silicon carbide to silicon oxycarbide was observed. X-ray diffraction confirms the presence of nanocrystalline material. Measurements showed that the origin of the photoluminescence may be to a combination of quantum confinement effects and defects in the silicon oxycarbide matrix, mainly those related to oxygen deficient centers and hydrogen and carbon-related defects. The obtained results are promising for the development of light emitting devices compatible with current technologies at low cost.