高吸收效率太阳能电池陷光机制和光学特性研究

发布时间：2018-07-21 11:31

【摘要】：太阳能的有效利用能够缓解当前的能源危机和环境污染这两大社会问题。太阳能电池可以直接将太阳能转换为电能,但是在当今社会中并没有得到广泛应用,究其主要原因是太阳能电池的转换效率过低和生产成本过高。因此,提高转换效率和降低生产成本是今后太阳能光伏技术发展的方向和目标。微纳结构在光伏器件上的应用能够极大地减小电池吸收层的厚度,从而降低其生产成本。为了提高太阳能电池的光电转换效率,很多研究工作都集中在新型光伏材料和陷光结构的研发当中。本文以太阳能电池的陷光结构为研究对象,设计出了纳米针光栅阵列和倾斜纳米线阵列的新型陷光结构,并且还建立了球形金属颗粒的表面等离子模型。通过数值仿真,对它们进行了光学特性和陷光机理的研究。本文的主要研究内容和结果如下:首先,针对GaAs纳米针光栅阵列,系统地研究了光栅阵列的结构参数对光吸收的影响。研究结果表明,光栅阵列的光吸收性能受结构参数的影响很大,经过优化后的光栅结构在所考察的波长范围内可以引起很宽波段内的光吸收增强。在最优参数配置下,纳米针光栅阵列的光吸收率最高可达到98%,与矩形光栅阵列相比提高了20%以上。其次,提出了倾斜GaAs纳米线阵列的陷光结构。利用有限元方法,研究了倾斜纳米线阵列的直径和填充因子对光吸收特性的影响,并且优化了该倾斜纳米线阵列结构。优化后的倾斜纳米线阵列,总吸收率最大可达到95%,短路电流可达到30.3mA/cm2。与竖直纳米线阵列相比,倾斜纳米线阵列的光学性能得到了很好的提高,这说明将纳米线阵列做成倾斜结构,可以提高纳米线阵列的陷光能力。最后,建立了以晶体硅为背景材料的金属颗粒表面等离子陷光模型,并且分析了金属颗粒的镶嵌位置、直径以及填充因子对晶体硅光学特性的影响。结果表明,硅材料的吸收率受金属颗粒直径和填充因子的影响很大,而受镶嵌位置的影响很小。直径和填充因子主要影响吸收峰的数目。为了探究光吸收增强的陷光机制,对吸收峰的产生机理进行了分析。在晶体硅薄膜层里加入金属颗粒,能够在一定程度上提高晶体硅的光吸收能力。
[Abstract]:The effective use of solar energy can alleviate the current energy crisis and environmental pollution two major social problems. Solar cells can convert solar energy to electric energy directly, but it is not widely used in the society today. The main reason is that the conversion efficiency of solar cells is too low and the production cost is too high. Therefore, to improve conversion efficiency and reduce production costs is the direction and goal of solar photovoltaic technology in the future. The application of micro-nano structure in photovoltaic devices can greatly reduce the thickness of the absorber layer of the cell and thus reduce the production cost. In order to improve the photovoltaic conversion efficiency of solar cells, a lot of research work is focused on the research and development of new photovoltaic materials and trapped light structures. In this paper, a novel trapping structure of nanoscale grating array and tilted nanowire array is designed, and the surface plasma model of spherical metal particles is also established. By numerical simulation, the optical properties and trapping mechanism are studied. The main contents and results of this paper are as follows: firstly, the influence of the structure parameters of the grating array on the optical absorption is systematically studied for the GaAs nano-needle grating array. The results show that the optical absorption performance of the grating array is greatly affected by the structure parameters, and the optimized grating structure can lead to the enhancement of the optical absorption in a wide wavelength range. Under the optimal configuration, the photoabsorption rate of the nanoscale grating array can reach 98%, which is more than 20% higher than that of the rectangular grating array. Secondly, the trapping structure of inclined GaAs nanowire arrays is proposed. The influence of the diameter and filling factor of the tilted nanowire array on the optical absorption characteristics was studied by using the finite element method, and the structure of the tilted nanowire array was optimized. The optimized tilted nanowire array has a maximum absorptivity of 95 and a short-circuit current of 30.3 Ma / cm ~ 2. Compared with the vertical nanowire array, the optical properties of the inclined nanowire array are improved, which indicates that the oblique structure of the nanowire array can improve the trapping ability of the nanowire array. Finally, a plasma trapping model of metal particle surface with crystalline silicon as the background material is established, and the influence of the inlay position, diameter and filling factor of metal particles on the optical properties of silicon crystal is analyzed. The results show that the absorptivity of silicon is greatly influenced by the diameter of metal particles and the filling factor, but not by the inlay position. Diameter and filling factor mainly affect the number of absorption peaks. In order to explore the trapping mechanism of light absorption enhancement, the mechanism of absorption peak was analyzed. The addition of metallic particles into the crystalline silicon film layer can improve the optical absorption ability of the crystal silicon to a certain extent.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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