H.D. Yang
金属学报(英文版)
Raman spectra and scanning electron microscope (SEM) techniques were used to determine the structural properties of microcrystalline silicon (μc-Si:H) films deposited on different substrates with the very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) technique. Using the Raman spectra, the values of crystalline volume fraction Xc and average grain size d are 86%, 12.3nm; 65%, 5.45nm; and 38%, 4.05nm, for single crystalline silicon wafer, corning 7059 glass, and general optical glass substrates, respectively. The SEM images further demonstrate the substrate effect on the film surface roughness. For the single crystalline silicon wafer and Corning 7059 glass, the surfaces of the μc-Si:H films are fairly smooth because of the homogenous growth or little lattice mismatch. But for general optical glass, the surface of the μc-Si:H film is very rough, thus the growing surface roughness affects the crystallization process and determines the average grain size of the deposited material. Moreover, with the measurements of thickness, photo and dark conductivity, photosensitivity and activation energy, the substrate effect on the deposition rate, optical and electrical properties of the μc-Si:H thin films have also been investigated. On the basis of the above results, it can be concluded that the substrates affect the initial growing layers acting as a seed for the formation of a crystalline-like material, and then the deposition rates, optical and electrical properties are also strongly influenced, hence, deposition parameter optimization is the key method that can be used to obtain a good initial growing layer, to realize the deposition of μc-Si:H films with device-grade quality on cheap substrates such as general glass.
关键词:
hydrogenated
,
甚高频等离子体增强化学气
魏晓丽
,
张玲
,
陈厦平
,
王辅明
表面技术
doi:10.16490/j.cnki.issn.1001-3660.2016.05.024
目的：通过疏水性质的研究，证明源电极式和浸入式 PECVD 方法制备含氢 DLC 膜存在结构和性质上的差别，并且证明浸入式PECVD方法制备的含氢DLC膜更适于需要强疏水性的表面改性应用。方法在PECVD腔体中通入甲烷和氢气混合气体，同时在面对源电极的绝缘样品架上放置石英基片并沉积类聚合物DLC膜；在源电极上放置石英基片并沉积常规含氢DLC膜。在PECVD腔体中通入乙炔、氢气和四氟化碳混合气体，在面对源电极的绝缘样品架上放置石英基片并沉积掺氟 DLC 膜。改变气体压强和射频功率，生长一系列含氢DLC膜。利用紫外可见近红外光度计测试DLC膜的透射谱，扫描电子显微镜及原子力显微镜测试其表面形貌。利用接触角测量仪测试两种含氢DLC和一种掺氟DLC膜表面与水、甘油、乙二醇的接触角，并计算其表面能。比较两种含氢DLC膜接触角和表面能的差别，并根据类聚合物DLC膜的微观结构分析可能的原因。比较掺氟和不掺氟DLC膜的接触角并讨论比较结果。结果类聚合物DLC膜的接触角和表面能与具有相同光学带隙的常规含氢DLC膜存在明显差异。类聚合物DLC膜的接触角更大，表面能更低，因而具有更强的疏水性。类聚合物和常规含氢DLC膜与蒸馏水的接触角最大分别为91.2°和79.2°。类聚合物DLC膜中的碳原子具有更高的氢化率，可能是它表面能低和疏水性好的原因。掺氟DLC膜的接触角比具有相同带隙的类聚合物和常规含氢DLC膜都低，这与文献报道的掺氟能提高接触角的现象完全相反。结论类聚合物DLC膜的疏水性更强。结合其更小的内应力、更宽的光学带隙范围和更快的生长速度等特征，使它在医疗、光学保护涂层等领域具有更强的应用性。浸入式 PECVD 方法生长的掺氟 DLC 膜不但未提高反而降低了 DLC膜的疏水性，需要更多的研究来揭示其中的原因。
关键词:
类金刚石
,
PECVD
,
含氢
,
掺氟
,
带隙
,
接触角
,
疏水性
李广忠
,
汤慧萍
,
张文彦
,
李纲
,
赵培
稀有金属材料与工程
氢化处理TiO2纳米管是一种简单而又有效地提高其光解水制氢效率的方法.通过采用FE-SEM、TEM、XRD及XPS等研究,在大气气氛500℃热处理后,接着经300℃氢化处理后,获得了由以锐钛矿组成的TiO2纳米管壁,和在纳米管内壁上高度无序的表面层组成的双相结构的TiO2纳米管阵列,且在纳米管表面形成了Ti-OH能带.光催化分解水试验表明,在光强为100 mW/cm2的模拟太阳光照射下氢化处理后的TiO2纳米管光阳极的光电流密度可达4.88mA/cm2,较未氢化处理的样品提高了约4倍.
关键词:
TiO2纳米管
,
光阳极
,
氢化处理
,
光催化分解水
,
氢气
