Fabrication and photoluminescence properties of continuous freestanding SiC(Al) films

The perfect and dense continuous freestanding SiC(Al) films were synthesized using the innovative technique of melt spinning of precursor. Polyaluminocarbosilane (PACS) was melt spun, cured and pyrolysis treated in the inert gas at high temperature. The microscopic surface and cross-section of resulting freestanding SiC(Al) films were investigated by SEM (scanning electron microscope), and their composition and microstructure were characterized by Electron Probe Microanalysis (EPMA), Raman spectrometer, FTIR (fourier transform infrared spectrometer), HRTEM (high resolution transmission electron microscope) and XRD (X-ray diffractometer). Photoluminescence (PL) spectra of the films were observed in the visible range at room temperature. The results showed that continuous freestanding SiC(Al) films contained p-SiC crystals, C clusters and α-SiC nano-crystals. The PL spectrum showed a wide luminescence band from 320 to 440 nm, and PL intensity increased with increasing sintering temperature. The origin of PL centered at 385 nm might be related to the α-SiC nano-crystals using quantum size effects. And the peak at 412 nm was also ascribed to the C clusters.