Synthesis and photoluminescence properties of continuous freestanding SiC(Al) films derived from aluminum-containing polycarbosilane

Continuous freestanding SiC(Al) films were fabricated by melt spinning the aluminum-containing polycarbosilane (A-PCS) precursor. The results showed that the films contained β-SiC crystals, α-SiC nano-crystals, C clusters and small amount of Al4O4C and Al4SiC4. The Al atoms in the films played important roles as both sintering aids and grain growth inhibitor. The PL spectrum showed a wide luminescence band from 320 nm to 440 nm, and the origin of PL centered at 385 nm might be related to the α-SiC nano-crystals using quantum size effects. The obtained films are expected to have important applications in MEMS for the environment of high temperature and optoelectronic devices.