Combustion synthesis of Si2N2O powder for photovoltaic silicon casting application

Abstract Single-phase silicon oxynitride (Si2N2O) was prepared in a N2 atmosphere by combustion synthesis with Si and SiO2 as the reactants. The effects of process parameters, including N2 pressure, Si2N2O diluent and NH4Cl content, on the combustion temperature, as well as phase composition and microstructure of products were investigated. The high-temperature wetting behavior of Si melt on the as-prepared Si2N2O coating was then tested by the sessile drop method. It was found that Si melt shows poor wettability to Si2N2O coating at 1500 °C with the steady contact angle of 120°, indicating that the combustion-synthesized Si2N2O powders could be used as a potential novel releasing agent material for photovoltaic silicon casting application.