Characteristics and properties of metal aluminum thin film prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

Metal aluminum (Al) thin films are prepared by 2450-MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas. We focus our attention on the plasma source for thin-film preparation and annealing of as-deposited films related to the surface square resistivity. The square resistivity of as-deposited Al film is greatly reduced after annealing and almost reaches the value of bulk metal. Through chemical and structure analysis we conclude that the square resistivity is determined by neither contaminant concentration nor surface morphology, but by both crystallinity and crystal size in this process.     

The influence of the structures and compounds of DLC coatings on the barrier properties of PET bottles

To reduce the oxygen transmission rate through a polyethylene terephthalate (PET) bottle (an organic plastic) diamond-like carbon (DLC) coatings on the inner surface of the PET bottle were deposited by radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) technology with C₂H₂ as the source of carbon and Ar as the diluted gas. As the barrier layer to humidity and gas permeation, this paper analyses the DLC film structure, composition, morphology and barrier properties by Fourier transform infrared, atomic force microscopy, scanning electron microscopy and oxygen transmission rate in detail. From the spectrum, it is found that the DLC film mainly consists of sp³ bonds. The barrier property of the films is significantly relevant to the sp³ bond concentration in the coating, the film thickness and morphology. Additionally, it is found that DLC film deposited in an inductively coupled plasma enhanced capacitively coupled plasma source shows a compact, homogeneous and crack-free surface, which is beneficial for a good gas barrier property in PET bottles.     

Characteristics and properties of metal aluminum thin films prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

Metal aluminum (Al) thin films are prepared by 2450 MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas. We focus our attention on the plasma source for the thin-film preparation and annealing of the as-deposited films relative to the surface square resistivity. The square resistivity of as-deposited Al films is greatly reduced after annealing and almost reaches the value of bulk metal. Through chemical and structural analysis, we conclude that the square resistivity is determined by neither the contaminant concentration nor the surface morphology, but by both the crystallinity and crystal size in this process.     

大气压射流等离子体中O及OH自由基的发射光谱在线诊断

OH自由基及氧原子在大气化学、表面处理及化学污染物分解等方面有着重要的作用。利用发射光谱技术在线测量了大气压射流等离子体中OH自由基紫外波段与O自由基777,844 nm波段的发射光谱。研究了OH自由基与氧原子光谱强度随放电功率及放电体系中所加入的氧浓度的变化。将实验测得的OH自由基光谱图与用Lifbase数据库模拟光谱图进行比较,估算了OH自由基的转动温度。结果表明:OH自由基的转动温度随放电功率的增加而增加,随工作气体流速的增加而减小。     

Insights of Unconventionally Long Exposure Time in Atomic Layer Deposition Al2O3 to Modify SnO2 Photoanode of Dye-Sensitized Solar Cells

Porous SnO2 photoanodes coated by alumina through atomic layer deposition technology are reported. It is found that when the dosing time of precursor is extended over 11 s, the 125% maximum increase of cell emciency is achieved. It is believed that besides the interracial charge recombination being efficiently suppressed by this ultra-thin coating, the increased absorption of dyes and elimination of the high density of monoenergetic surface states on SnO2 might play a positive role in improving the cell efficiency. The reason is that a long exposure time of precursor can guarantee the 100% coverage of Mumina on porous SnO2, which is further explained by a built three-step model. Then we conclude that for a high cell efficiency in porous photoelectrode a long exposure time is indispensable.     

多腔耦合微波表面波PECVD法沉积DLC薄膜研究

报道了利用多腔耦合微波表面波等离子体增强化学气相沉积(PECVD)的方法制备类金刚石(DLC)薄膜。通过发射光谱(OES)测量,对Ar等离子体中的各种放电参数以及全部四个腔室内放电的均匀性作出评估。采用表面轮廓仪测量了薄膜的厚度;薄膜的表面形貌、组成结构通过原子力显微镜(AFM)、激光拉曼光谱和X射线衍射光谱(XPS)进行了表征。在12.5μm厚度的有机薄膜聚酯(PET)表面沉积一定厚度DLC后,通过测量水蒸气透过率(WVTR)对DLC薄膜的阻隔性能进行了研究。结果表明,这种多腔耦合微波表面波等离子体装置,不仅能够实现四个腔室同时相对均匀的放电,也能够实现单个腔室的轴向均匀放电。制备的DLC薄膜结构致密、成分均匀,可以使PET薄膜阻隔性能提高约20倍。     

建立多渠道投资机制促进实验室建设

在国家教委颁布的《关于加强高校实验室工作意见》文件中指出：“实验室建设是办好高校、培养合格人材的一项基础性工作”。实验室在育人方面有其独特作用,不仅可以授人知识和技术,培养学生动手能力、分析问题与解决问题的能力,而且影响人的世界观、思维方法和作风。近代科技发展史表明,对经济建设有重大影响的发明,多数来自实验室,愈是现代科技愈是依靠科学实验来发展。可见,实验室在高等学校有着重要的地位。加强实验室建设,其中实验室建设经费是最重要的物质基础,为了学科建设,改善实验室的教学条件,我校采取了以下措施。　１…