【作者】 王雪；

【导师】 秦应雄；

【作者基本信息】 华中科技大学 ， 物理电子学， 2015， 硕士

【摘要】 激光掺杂选择性发射极技术是提高太阳电池转换效率的重要方法之一,本文从理论出发建立了扩散模型和激光掺杂模型,进行了激光掺杂实验,分析了激光掺杂提高电池转换效率的机理。本文的主要内容包括:(1)分析了选择性发射极结构相对于传统电池结构的特点和优点,讨论了选择性发射极结构改善电池开路电压、短路电流、少子寿命以及电池转换效率的机理。(2)从理论出发,建立了扩散模型,并研究了激光与晶体硅的相互作用,建立了热源模型、熔池模型以及方阻模型,为选择性发射极太阳电池的发射极区和电极区的方阻分布设计优化了参数。(3)以现有太阳电池基本制造工艺技术为基础,进行了激光掺杂选择性发射极实验。实验采用波长为532nm的脉冲激光器对晶体硅片进行掺杂。激光掺杂后硅片方阻值出现明显降低,而且增大激光器工作电流,硅片方阻值下降更加明显。实验测试了晶体硅太阳电池的外量子效率,外量子效率在短波段有显著提高,最高提高18%。研究了激光掺杂后晶体硅电池的光电转换特性,电池转换效率有所改善,平均提高0.15%~0.34%。(4)激光器工作电流过大时,容易导致电池片失效,降低电池成品率。针对这一问题设计了重掺杂区域形状以及激光掺杂掩膜板,这一设计不仅可以提高电池成品率和可以提高激光掺杂效率。本文激光掺杂实验结果表明,激光掺杂技术对电池方阻、外量子效率以及转换效率均有所改善,对高效选择性发射极太阳电池产业化具有一定的参考价值。更多还原

【Abstract】 Laser doping selective emitter technology is one of the important methods to improve conversion efficiency of photovoltaic cells. In this paper, diffusion model and laser doping model are built theoretically. Laser doping experiments is conducted, and the mechanism of how elective emitter technology improves the conversion efficiency of photovoltaic cells is analyzed. The main contents of this paper include:(1) The analysis of the features and advantages of the selective emitter structure compared with traditional battery structure and the discussion about the mechanism of how selective emitter technology improves the open circuit voltage, short circuit current, the fill factor, the spectral response and the conversion efficiency of the cell.(2) Diffusion model is built theoretically. The interactions of laser and crystal silicon are researched based on the heat conduction theory, and the heat source model, weld crater model and sheet resistance model are built, so the parameters of the design, which for the distribution of sheet resistance in the emitter region and electrode areas of selective emitter solar cell, are optimized.(3) Laser doping selective emitter experiment is conducted based on the existing solar cells manufacturing technology. Nanosecond pulsed laser with a wavelength of 532 nm was used to conduct laser doping on crystalline silicon wafers which remains phosphosilicate glass after diffusion. The sheet resistance decreased about 50%, and with the increasing of laser power, the sheet resistance decreased more significantly. The external quantum efficiency of the laser-doped solar cells was tested and is improved by 18% to the highest in the short wavelength band compared to conventional solar cells. The photoelectric conversion characteristics of laser-doped polycrystalline silicon cells were studied, and the conversion efficiency of the battery has improved by an average of 0.15%-0.34%.(4) When the laser working current is too large, it’s easy to cause the battery failure and reduce the yield of battery. The shape of heavily doped region and laser doping mask are designed in order to solve this problem. It can not only improve the yield of battery, but also can improve the efficiency of laser doping.The results of laser doping experiment in this paper show that: sheet resistance of the battery, the external quantum efficiency and conversion efficiency are improved by laser doping technique. Therefore, it has certain reference value for high efficiency selective emitter solar cells industrialization.更多还原