空气环境下退火温度对连续SiC自由膜结构与发光特性的影响

Influence of Annealing Temperature on the Structure and Photoluminescence Properties of Continuous Freestanding SiC Films in Air

采用熔融纺膜与先驱体转化法相结合制备出连续SiC自由薄膜,研究薄膜在1300,1400,1500℃温度下空气退火处理的氧化行为,以及退火温度对薄膜微观结构、光致发光特性(PL)、硬度和电阻率的影响。结果表明,SiC薄膜在1300℃具有较佳的抗氧化和发光特性,随着退火温度的升高,薄膜的抗氧化和发光特性略有降低,薄膜中无定型SiOxCy减少,-βSiC晶粒长大及游离碳增多,薄膜表面硬度与电阻率下降,表面惰性致密氧化层的生成保护阻挡氧扩散,从而有效减缓薄膜进一步被氧化。

Continuous freestanding SiC films were successfully prepared by melt spinning of precursor.The films were annealed in air at 1300,1400℃ and 1500℃,respectively.The effect of annealing temperature on the microstructure,oxidation behavior,photoluminescence,hardness and electrical resistivity of freestanding SiC films were studied.The results show that the specimens after being annealed at 1300℃ for 1h exhibit excellent oxidation resistivity and PL performance.And the dense oxide layer produced by the rapid oxidation of SiC can effectively protect the specimens against the further oxidation attack.Oxidation resistivity,PL intensity and surface hardness of films decrease slightly with the increase of annealing temperature was due to a combination of formation of dense outer oxide layer,crystal growth of β-SiC,decomposition of amorphous SiOxCy and increase of free carbon phase.