C（膜）/Si（SiO₂）（纳米微粒）/C（膜）夹层膜的结构及其光致发光性质研究

【作者】 邱晓燕；

【导师】 李建；

【作者基本信息】 西南师范大学 ， 凝聚态物理， 2001， 硕士

【摘要】 本文首先简要介绍了当前硅基发光材料的发展概况，研究了硅基发光材料常见的几种光致发光理论模型。在比较综合硅基发光材料常见制备方法优缺点的基础上，用直流辉光溅射法结合真空镀膜法制备出C（膜）/Si（SiO₂）（纳米微粒）/C（膜）夹层膜。本文详细解释了夹层膜的制备方法和加热退火处理过程。用透射电子显微镜（TEM），扫描电子显微镜（SEM）观察样品的形态结构；用X-射线衍射仪（XRD）对样品进行物相分析；用X-射线光电子能谱（XPS）对样品进行元素价态分析，较全面地分析研究了样品的形态结构和物相成分。利用荧光分光光度计和激光喇曼谱仪（LRS）研究了样品的光致发光（PL）特性和喇曼光谱特性，并从机理上进行了初步探讨。 在样品的制备方面主要取得了以下研究结果： 在硅基发光材料常见的颗粒膜或多层膜结构基础上，设计出C（膜）/Si（SiO₂）（纳米微粒）/C（膜）这种膜夹微粒的“多层三明治结构”。采用直流辉光溅射法结合真空镀膜法制备出了夹层膜样品。实验证明，这种形似量子阱的结构具有不同于其它硅基发光材料的独特的光致发光性质。 通过TEM、SEM、XRD和XPS全面研究夹层膜的形态结构发现： （1）Si（SiO₂）纳米微粒基本呈球形，粒径在30nm左右。样品总厚度约50μm。 中文摘要 门)在 4 0 0 C加热后，膜表面出现孔状结构；6 5 0 C加热后，膜表面微粒大小最均匀，结合最致密。 （3）由于遭到氧化，膜内微粒形成外壳为 SIO；，内核为 St的两相结构。在C原子的还原作用和氧气的氧化作用的共同作用下，S i O／乃 i的比值随加热温度的升高而呈现交替变化：400C时，C的还原作用占主导地位，SIO；几乎全部被还原成了St，SIO／引的比值最低；650C时，氧化作用占主导地位，SIO／引的比值最高。 门)在加热过程中，C原子扩散进入引 （SI；）a层，在 650C与幻反应生成了不同于常见晶体结构的引。 在样品的光致发光特性方面，主要研究结果如下： （1）在波长为250urn的紫外辐射激发下，刚制备出来的样品在398urn（3．12eV）处有一宽带紫光 PL；峰。经 650C退火后，又出现了一个峰位位于 360urn（3·44eV）附近的PL；肩峰。 （2）PL峰形状和峰位不随退火温度的变化而变化，但强度却随退火温度变｛t而发生变化：4 0 0 oC kX T，P L峰强度降低；4 0 0 oC时比峰强度为零；400－650oC，PL峰强度增加；6 5 0 C后，PL峰强度又开始降低。 （3）PL峰形状和峰位不随激发波长的变化而变化，但随着激发波长的增加，PL峰强度逐渐降低。 在样品的光致发光机理方面，取得以下研究结果： 门)峰位在 398urn门．1uV)的宽带紫光 PL；峰的光激发发生在引；微粒内 部，而光发射源于u；与引界面上的缺陷中。。PL；峰的强度与剔 ／沾 的比例成 正比． 门)峰位位于 360urn（3．44eV）附近的紫外荧光 PL；肩峰源自引 内部的电子－空穴复合发光。 本文研究证明：用直流辉光溅射法和真空镀膜法制备C（膜）亿 门 ＊ G米微粒)儿（膜）夹层膜的方法是可行的，其膜夹微粒的结构使其具有其它硅基发光材料不具有的紫光波段的光致发光特性。更多还原

【Abstract】 Above all, this paper briefly introduces the development survey of silicon-based luminescence matter in recent years, then sums up some common phtoluminescence theory models. After comparing some common preparation methods, C(film)/Si(Si02)(nanometer particles)/C (film) (abbr. C/Si(Si02)IC) is fabricated by sputtering silicon on the amorphous carbon film in Ar gas firstly, then depositing amorphous carbon film on silicon particles layer in vacuum. Finally, it is annealed at different temperatures (27?50). The configuration of sample is studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM); the matter phase is analyzed by X-ray diffraction (XRD); the element valence is tested by photoelectron spectroscopy (XPS); the photoluminescence (PL) and Raman spectrum are tested by fluorescence spectrophotometer and laser Raman spectrograph (LRS)respectively. Lastly, the photoluminescence mechanism is preliminarily discussed. The achievements of experiments are listed as follow: The sample has special ulti-layer sandwich structure s film/ particles/film is successfully fabricated by direct current (D.C.) glow sputtering in Ar gas and depositing in vacuum. At the aspect of configuration, we find: (1) Si(Si02) nanometer particles are spherical on the whole, whose diameter is about 30 nm. The thickness of the sample is about 5Oprn totally. (2) Hole structure is found on the surface of sample after heated at 400~扖. The particles on the surface are well-distributed and compacted after heated at 650扖. (3) Because of oxidation, Si02 surrounds Si particles during sputtering. Caused by the oxidation and carbon atoms?reduction during heating , the ratio of Si02/Si alternately changes with the increase of annealing temperature: the reduction occupies dominant position at 400扖, Si02 is reduced to Si by C, so the rate of Si02/Si is lowest; the oxidation occupies dominant position at 650, Si is oxidized to Si02, so the rate of Si02/Si is highest. (4) Carbon atoms diffuse into Si(Si02) particles layer during heating and produce SiC by reacting with Si at 650. At the aspect of photoluminescence, the achievements are listed as follows: (1) Excited by 250nm UV- light, the sample gives a strong PL1 band around 398nm (3.12eV), another weak PL2 band around 360nm(3.44eV) is only found after annealing at 650. (2) The shape and peak position of PL is independent on annealing temperature ,but the intensity is strongly dependent on it: the intensity decrease below 400C, and is lowest at 4000C; it increase between 400-650, and decrease again beyond 650. (3) The intensity of PL decreases with the increase of excited wavelength. At the aspect of photoluminescence mechanism, the achievements are listed as follows: (1) The excitation of photons of PL1 band occurs inside Si02 nanometer particles, but the emission of photons comes from the defects at the interface between Si02 and Si. The intensity of PL1 band is directly proportional to the ratio of SiO]Si. (2) PL2 band is due to electron-hole recombination inside SiC nanometer particles. Passing through this paper study, the conclusion is: Fabricating C/Si (Si02)/C by D.C. glow sputtering in Ar gas and depositing in vacuum is permitted. The ulti-layer sandwich structure?contributes to the violet-light poto-更多还原