飞秒激光制备黑硅材料的实验研究

发布时间：2018-02-26 00:11

本文关键词： 飞秒激光黑硅材料碱溶液反射率尖峰结构　出处：《北京工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：黑硅作为一种新型硅材料,在可见光区域具有极强的光吸收能力,所以在太阳能电池、光探测等领域有着巨大的应用前景。近些年来,黑硅材料得到了业界的广泛关注,其制备方法也成为当前的研究热点。黑硅材料的制备方法多种多样,但都有各自的不足,本文提出了一种制备黑硅材料的新方法,即在碱溶液中利用飞秒激光制备黑硅,通过实验,获得了较理想的实验结果,证明了此实验方法的有效性。论文中通过实验探究了实验参数对黑硅表面形貌和反射率的影响,这一实验结果对激光制备黑硅表面微结构的形态控制以及材料应用等方面都有着重要的意义。主要工作概括为以下几点:1.搭建了在碱溶液中利用飞秒激光制备黑硅的实验装置,制得的黑硅样品,在原子力显微镜下观察到丛林状尖峰结构,与抛光硅相比,黑硅样品可以大大降低反射率。2.实验研究了扫描速度对黑硅材料反射率的影响,发现在0.1 mm/s、0.5mm/s和1.0 mm/s的三种扫描速度中,当激光能量相同时,扫描速度越慢,其样品的反射率越低。3.在探究飞秒激光脉冲能量对黑硅表面形貌和反射率的影响时,实验中激光能量的变化范围为400 2000μJ,分析尖峰高度随激光能量的变化发现,随着激光能量的增加,尖峰的高度是先增加后降低。通过分析反射率随激光能量的变化发现,随着激光能量的增加,反射率是先降低后增加。通过实验获得了最佳的激光能量值,即1400μJ,此时黑硅样品的尖峰高度最大,反射率最低,大约为5.6%。4.在碱溶液中利用飞秒激光制备黑硅,此方法与Mazur实验室的制备方法相比,避免了昂贵的真空设备,并且不会产生SF6、H2S等剧毒气体,因而不会对人体和环境造成危害。与在硫酸中制备黑硅的方法相比,此实验中选择的是2 wt%的Na OH溶液,这是低浓度碱,不会污染水体和土壤。且此方案实验设备简单、易操作,碱溶液价格低廉,其成本远远小于六氟化硫气体。
[Abstract]:Black silicon, as a new type of silicon material, has very strong optical absorption ability in the visible region, so it has a great application prospect in solar cells, light detection and other fields. In recent years, black silicon materials have been widely concerned by the industry. In this paper, a new method of preparing black silicon material is proposed, which is to use femtosecond laser to prepare black silicon in alkali solution. The experimental results show that the method is effective. The influence of experimental parameters on the surface morphology and reflectivity of black silicon is investigated. The experimental results are of great significance to the morphology control and material application of the surface microstructure of black silicon prepared by laser. The main work is summarized as follows: 1. An experimental device for preparing black silicon by femtosecond laser in alkaline solution has been built. The bushlike peak structure of the black silicon sample was observed under atomic force microscope. Compared with polished silicon, the black silicon sample can greatly reduce the reflectivity. 2. The effect of scanning speed on the reflectivity of black silicon material is studied experimentally. It was found that in the three scanning velocities of 0. 1 mm / s 0.5 mm / s and 1. 0 mm/s, the slower the scanning speed was, the lower the reflectivity of the sample was when the laser energy was the same. The effect of femtosecond laser pulse energy on the surface morphology and reflectivity of black silicon was investigated. In the experiment, the range of laser energy is 400 渭 J. It is found that the peak height increases first and then decreases with the increase of laser energy. It is found by analyzing the variation of reflectivity with laser energy. With the increase of laser energy, the reflectivity decreases first and then increases. The optimum laser energy value, i.e. 1400 渭 J, is obtained through experiments. The peak height of the black silicon sample is the highest and the reflectivity is the lowest. In alkaline solution, black silicon is prepared by femtosecond laser, which avoids expensive vacuum equipment and does not produce highly toxic gases, such as SF6H2S, compared with the method used in the Mazur laboratory. Compared with the method of preparing black silicon in sulfuric acid, the NaOH solution of 2 wt% is chosen in this experiment, which is low concentration alkali and does not pollute water and soil. The experimental equipment of this scheme is simple. Easy to operate, alkali solution low price, its cost is far less than sulfur hexafluoride gas.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2

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