低压化学气相沉积制备掺硼碳薄膜及其表征

PREPARATION AND CHARACTERIZATION OF BORON DOPED CARBON THIN FILM BY LOW PRESSURE CHEMICAL VAPOR DEPOSITION

以 BCl3和 C3H6分别作为低压化学气相沉积制备掺硼碳材料的硼源和碳源,采用热壁化学气相沉积炉,于 1 100 ℃在碳纤维基底上制备了掺硼碳薄膜。采用扫描电镜、X 射线衍射和 X 射线光电子能谱对样品作了表征。结果表明:产物表面光滑,断面呈细密的片层状结构,产物由 B4C 和石墨化程度较高的热解碳组成。采用掺硼碳薄膜中含有 15%(摩尔分数,下同)硼。硼原子化学键结合状态共有 5 种,分别是:B4C 的中的 B—C键,硼原子替代固溶在类石墨结构中形成的 B—C键,BC2O 和 BCO2结构中 B—C键和 B—O键的混合态,以及 B2O3中的 B—O键。其中超过 40%的硼原子以替代固溶的形式存在于热解碳的类石墨结构中。

Boron doped carbon （BCx） thin film was prepared at 1 100 ℃ on carbon fiber substrate by low pressure chemical vapor deposition （LPCVD） from BCl3 and C3H6 as boron and carbon sources respectively. Scanning electron microscopy observation results show that the BCx coating has a smooth surface and the cross section of BCx coating exhibits a very fmely laminated structure. X-ray diffraction analysis results show that the BCx coating consists of B4C and pyrolytic carbon with a high degree of graphitization. X-ray photoelectron spectroscopy results show that there is 15% （in mole, the same below） boron induced in the BCx coating. Five different chemical surroundings of boron atoms were confirmed in the BCx coating, namely, BaC, boron atoms substituted in the graphite-like structures, and mixtures of B-C bonding and B-O bonding referred to as BC2O and BCO2, B2O3, respectively. More than 40 % of boron atoms are included by substitution in the graphitic-like structure.