Synthesis and characterization of continuous freestanding silicon carbide films with polycarbosilane (PCS)

A technique based on melt spinning of precursor was introduced to produce continuous freestanding SiC films. An equipment including spinneret, mandril, tank and seal groove was designed and manufactured for melt spinning. The polycarbosilane (PCS) precursors were deaerated, melt spun, crosslinked (by oxidation or irradiation), and pyrolyzed at high temperature in order to convert the initial PCS into freestanding SiC films. Our results revealed that the continuous freestanding SiC films, approximately 8 μm to 190 μm in thickness depended on setting, were uniform and dense. Their microstructure consisted of amorphous SiOxCy, β-SiC nano-crystals and free carbon. The photoluminescence (PL) spectrum showed two blue emissions at 416 nm and 435 nm. The continuous freestanding SiC films with high modulus, high density, high surface hardness and optoelectronic properties may have potential applications in microelectromechanical systems (MEMS), advanced optoelectronic devices and such complex-shaped materials.