【作者】 陈达；

【导师】 李清山；

【作者基本信息】 曲阜师范大学 ， 物理电子学， 2006， 硕士

【摘要】 本论文系统研究了采用KrF准分子脉冲激光沉积技术制备无氢类金刚石膜的工艺和性质,通过优化实验参数,获得了质量较高的类金刚石膜,并进一步在氧气氛围中制备了sp³含量更高的纳米晶金刚石薄膜。这种薄膜中sp³键全部由C原子组成,具有较高的硬度、较好的化学稳定性和在红外、可见光区优良的透过性等类似金刚石薄膜的性能,具有很高的实用价值。论文的主要内容有: （1） 在不同激光功率密度和衬底温度下制备了无氢类金刚石膜,发现当激光功率密度降低或衬底温度升高时,样品Raman谱中的D峰增强,紫外一可见光透射率降低,光学带隙变窄。室温样品的热稳定性较好,高温样品在退火过程中会发生晶化形成石墨微晶,sp²成分增多。这说明沉积条件发生上述变化时,样品sp²相含量增多,sp²团簇的界域扩大,原子有序性增强。论文用C原子有序化模型解释了上述现象。 （2） 测量了无氢类金刚石膜的光致发光行为,发现低温沉积的薄膜存在可见光区的多个发光峰,而高温样品仅呈现单个较宽的发光峰,发光峰位和强度与Raman谱I（D）/I（G）的比值之间存在稳定的对应关系,样品发光峰随衬底温度升高而增强和红移。论文详细讨论了材料中局域电子状态和载流子的复合机制,认为样品的光致发光是由于不同界域的sp²团簇中局域载流子的辐射复合而产生的。 （3） 在适当压强的氧气氛中得到了纳米晶金刚石薄膜,薄膜具有较宽的1332cm^-1处金刚石的散射峰,说明样品中金刚石含量较高,但晶化程度较低,仅包含有纳米量级的晶粒。论文研究了不同氧气氛压强对薄膜结构和光学性质的影响,分析了氧气在生长过程中重要的化学和热力学作用。更多还原

【Abstract】 In this paper, lots of unhydrogenated DLC films were prepared by using a KrF excimer laser at different deposited condition. By optimizing the experiment parameters, the DLC films contained more sp³ sites were obtained. The mechanical hardness and the thermal stabilities of unhydrogenated DLC films with higher sp³ contents, which are used in a wide area of industrial applications, are much superior to those of most hydrogenated DLC films. There are some points as followed:（1） The Diamond like carbon films were prepared in the different conditions. When the laser energy density decrease or the deposition temperature increase, the D peaks in Raman spectra become stronger and the optical gap become narrow. Thermal stabilities of the samples deposited at RT were better than others. The experiment results indicate that the sp² sites increase and the clusters grow when the substrate temperature increase or the laser energy density decrease. The model of C atoms ordering was used to explain the growing mechanism.（2） The photoluminescence properties of unhydrogenated DLC films were deeply studied. The samples deposited at low temperature possess some luminescence peak in visible light. There is only one wide peak in the samples deposited at high temperature. The main band of photoluminescence shifts to short wavelength and the intensity of this band increase. The nature of localized states and the carrier recombination mechanism in the material were detail discussed. The photoluminescence can be attribute to carrier localization within an increasing sp² clusters.（3） The nano-crystal Diamond films were prepared in proper ambient pressure oxygen gases. There is a wide 1332cm^-1 peak in the Raman spectra,which indicated that, the sp content in films is high, but only some nano-crystal grain disperse on the films surface. The effects of ambient gases on the structure and properties are detail discussed. The ambient oxygen shows a strong etching sp2 effect in the growing progress.更多还原