基于光伏碳纳米管阵列的制备及其陷光性能初步研究

发布时间：2018-02-25 19:26

本文关键词： 碳纳米管阵列催化活性球形碳螺旋碳纤维陷光　出处：《燕山大学》2016年硕士论文　论文类型：学位论文

【摘要】：本文利用热化学气相沉积(TCVD)的方法在单晶硅衬底上,以镍为催化剂,通过碳源乙炔裂解制备了碳纳米管阵列(CNTs)薄膜。分别使用扫描电子显微镜(SEM)和透射电子显微镜(TEM)表征了CNTs的形貌;并讨论了催化剂、碳源气体流量、生长时间等因素对CNTs生长的影响;分析了它们的形成机制;最后对碳纳米管阵列的陷光性能进行了初步研究。实验中镍催化剂采用旋涂转移和磁控溅射两种方法制备。SEM结果表明利用单层聚苯乙烯(PS)微球,通过旋涂转移法在硅衬底上制备的镍催化剂具有规则的图案化形貌,磁控溅射法制备镍催化剂均匀且厚度可控。在生长定向CNTs时,催化剂厚度为5-10nm左右较为合适,催化剂厚度增加不利于CNTs的生长,是由于较厚的催化剂在高温时容易发生团聚,会导致催化剂失去催化活性。同时研究了碳源气体流量和生长时间对制备的CNTs影响,随着碳源气体流量的变大和生长时间的延长,制备的CNTs会发生管径变粗、高度增加的现象,但是生长时间超过20min后,碳纳米管高度不再继续增加,当碳源乙炔气体流量超过70sccm时,会导致实验制备不出碳纳米管。实验对于单温区不同位置碳源乙炔的裂解进行了研究,发现有温度梯度存在的情况下,高温管式炉中不同位置可以得到不同形貌的碳纳米管阵列和球形碳,分析了碳纳米管阵列和球形碳的形成机制以及形成差异的原因。使用镍/铜网、Ni(NO3)2/Cu(NO3)2和Ni(NO3)2/Fe(NO3)3三种不同的复合催化剂来催化裂解碳源乙炔,制备出了不同形貌的螺旋状碳纤维,探讨了螺旋结构的生长机制,并分析了催化剂活性对制备的碳纤维螺旋度的影响。利用紫外-可见分光光度计研究了CNTs薄膜和传统硅基太阳能电池表面结构的陷光性能,发现CNTs薄膜在波长200-800nm范围的紫外-可见光波段反射率仅为5%左右,其减反射性能明显优于单晶硅和多晶硅电池绒面结构。
[Abstract]:In this paper, nickel was used as catalyst on monocrystalline silicon substrate by thermochemical vapor deposition (TCVD) method. Carbon nanotube arrays (CNTs) thin films were prepared by acetylene pyrolysis. The morphology of CNTs was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The influence of growth time on the growth of CNTs and the mechanism of their formation were analyzed. Finally, the trapping properties of carbon nanotube arrays were preliminarily studied. In the experiment, the nickel catalyst was prepared by spin-coating transfer and magnetron sputtering. The SEM results showed that the single-layer polystyrene (PS) microspheres were used. The nickel catalyst prepared on Si substrate by spin-coating transfer method has regular patterned morphology, and the thickness of Ni catalyst prepared by magnetron sputtering method is uniform and controllable. The thickness of the catalyst is about 5-10nm when the growth orientation is CNTs. The increase of catalyst thickness is not conducive to the growth of CNTs, because the thicker catalyst is easy to agglomerate at high temperature, which will lead to the loss of catalytic activity. The effects of carbon source gas flow rate and growth time on the preparation of CNTs are also studied. With the increase of carbon source gas flow rate and the increase of growth time, the diameter and height of the prepared CNTs will increase, but after the growth time is more than 20 minutes, the height of CNTs will not continue to increase. When the flow rate of acetylene gas from carbon source exceeds 70 SCM, the carbon nanotubes can not be prepared experimentally. The pyrolysis of acetylene at different positions in the single temperature region is studied, and it is found that there exists a temperature gradient in the pyrolysis of acetylene. Carbon nanotube arrays and spherical carbon with different morphologies can be obtained in high temperature tube furnaces at different locations. The formation mechanism of carbon nanotube arrays and spherical carbon and the reasons for the difference in formation were analyzed. Three different kinds of composite catalysts, nickel / copper mesh nigno _ 3o _ 2 / cuno _ 3no _ 3O _ 2 and Ni(NO3)2/Fe(NO3)3, were used to catalyze the cracking of acetylene, and the spiral carbon fibers with different morphologies were prepared. The growth mechanism of helical structure and the effect of catalyst activity on the helicity of carbon fiber were discussed. The trapping properties of CNTs thin films and the surface structures of traditional silicon based solar cells were studied by UV-Vis spectrophotometer. It is found that the reflectivity of CNTs thin films in the wavelength range of 200-800 nm is only about 5% in the UV-Vis band, and its antireflection performance is obviously superior to that of single crystal silicon and polycrystalline silicon cell suede structure.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.1

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