Study of blue emission from Nano-SiC powders during rapid thermal annealing

Nanometric SiC powder was prepared by chemical vapor deposition at 1100 deg rees C, and samples were subsequently treated by rapid thermal annealing at 600-1100 degrees C. The intensities of the blue photoluminescence were the n measured at room temperature. The peak intensity at 2.56 eV (484 nm) rise s with annealing temperature, reaching a value about 9.2 times as high at 8 00 degrees C, then drops very quickly at 900 degrees C. Based on the result s of x-ray diffraction, infrared spectroscopy, x-ray photoelectron spectros copy and transmission electron microscopy, we conclude that the amounts of the twofold coordinated Si on the surface of the nanometric Sic particles p lay an important role in the photoluminescence intensity.