晶体硅太阳电池效率的光致衰减研究

发布时间：2018-10-26 07:11

【摘要】：随着晶体硅太阳电池制备技术的进步，产业化电池效率不断向实验室记录靠近。电池效率的提升依赖硅片的质量，而硅片的质量则主要是由其中的杂质和缺陷决定的，p型掺硼直拉单晶硅太阳电池在光照下会出现效率衰退现象，因此，提高晶体硅的品质并抑制光衰的措施和机制成为光伏领域研究的重要课题。 1、本文首先对掺镓、掺硼单晶硅中杂质和缺陷在退火过程中的行为及其对少子寿命的影响进行了系统研究，结果表明，在单步退火过程中，随着退火温度的升高，掺镓单晶硅和掺硼单晶硅中间隙氧含量都下降，掺镓单晶硅中间隙氧含量下降速率更快；氧沉淀腐蚀坑都增多，掺镓单晶硅的腐蚀坑尺寸小于掺硼单晶硅；少子寿命均下降，且低温退火下降速率更快。随着退火时间的延长，掺镓单晶硅和掺硼单晶硅中间隙氧含量也下降，氧沉淀腐蚀坑密度增加，少子寿命变化不大。两步退火过程中，随着第二步退火温度的升高，掺镓单晶硅和掺硼单晶硅中间隙氧含量和少子寿命下降速率加快。 2、研究了不同掺镓比例的直拉单晶硅及其太阳电池的性能，结果表明，，100%掺镓的单晶硅的少子寿命比100%掺硼单晶硅的高一倍，Ga、B共掺单晶硅的少子寿命较低。不同比例的掺镓单晶硅太阳电池的转换效率均达到了掺硼单晶硅太阳电池的水平，掺镓为80%时的太阳电池转换效率最高。 3、研究了镓对单晶硅太阳电池效率衰减的抑制作用，结果表明，随着掺镓比例的增加，直拉单晶硅太阳电池的光致衰减率降低，掺镓为100%时，光致衰减率最低，达到0.205%。由于镓的掺入，B-O复合体的浓度降低，抑制了太阳电池的光致衰减。
[Abstract]:With the progress of preparation technology of crystalline silicon solar cells, the efficiency of industrial solar cells is more and more close to the laboratory records. The improvement of cell efficiency depends on the quality of silicon wafer, and the quality of silicon wafer is mainly determined by the impurities and defects in it. The efficiency of p-type boron doped Czochralski silicon solar cells will decline under light. The measures and mechanisms of improving the quality of crystal silicon and inhibiting light decay have become an important subject in the field of photovoltaic research. 1. Firstly, the behavior of impurities and defects in gallium doped and boron doped monocrystalline silicon during annealing and their influence on minority carrier lifetime are systematically studied. The results show that, in the process of single step annealing, with the increase of annealing temperature, The gap oxygen content in gallium doped monocrystalline silicon and boron doped monocrystalline silicon decreases, while the gap oxygen content in gallium doped monocrystalline silicon decreases more rapidly. The corrosion pits of Gallium doped monocrystalline silicon are smaller than that of boron doped monocrystalline silicon, and the minority carrier lifetime is decreased, and the decreasing rate of low temperature annealing is faster. With the increase of annealing time, the gap oxygen content in gallium doped monocrystalline silicon and boron doped monocrystalline silicon also decreases, the density of oxygen precipitation corrosion pit increases, and the minority carrier lifetime does not change much. With the increase of the second step annealing temperature, the gap oxygen content and minority carrier lifetime decrease rate in gallium doped monocrystalline silicon and boron doped monocrystalline silicon are increased. 2. The performances of Czochralski silicon and its solar cells with different gallium ratio are studied. The results show that the minority carrier lifetime of 100% Gallium doped silicon is twice as high as that of 100% boron doped monocrystalline silicon, and the minority carrier lifetime of Ga,B co-doped monocrystalline silicon is lower than that of 100% boron doped monocrystalline silicon. The conversion efficiency of gallium doped silicon solar cells reaches the level of boron doped silicon solar cells, and the conversion efficiency of the cells with 80 gallium doping is the highest. 3. The inhibitory effect of gallium on the efficiency attenuation of monocrystalline silicon solar cells is studied. The results show that the photo-induced attenuation rate of Czochralski silicon solar cells decreases with the increase of gallium doping ratio, and the photo-induced attenuation rate is the lowest when the Gallium doping ratio is 100. Reach 0.205. Due to the addition of gallium, the concentration of B-O complex decreases, which inhibits the photo-induced decay of solar cells.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM914.4

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