退火和铝吸杂对太阳能多晶硅性能的影响.docVIP

 退火和铝吸杂对太阳能多晶硅性能的影响# 张俊峰1,2，陈秀华1，马文会2,3，张聪2,3，魏奎先2,3** （1. 云南大学 物理科学技术学院，云南 昆明 650091； 5 10 15 20 25 30 35 2. 昆明理工大学 真空冶金国家工程实验室，云南 昆明 650093； 3. 昆明理工大学云南省高校硅冶金与硅材料工程研究中心，云南 昆明 650093） 摘要：在不同的温度下对纯度为 99.999%的冶金法太阳能级多晶硅片分别进行退火和铝吸杂 实验研究，用金相显微镜和电子背散射衍射（EBSD）观察硅片的位错和晶界，用少子寿命 测试仪和四探针测试仪测试其少子寿命和电阻率变化情况。结果表明，在 600～1100条件 下退火和吸杂后的硅片位错密度明显降低，Σ3 型晶界比例在不断的增加，经退火后的电阻 率和少子寿命出现下降，而铝吸杂后的电阻率和少子寿命则是随温度的增加先升高再降低。 这说明对于此纯度的多晶硅来说，决定其少子寿命和电阻率主要因素不是位错和晶界，而是 杂质的含量；铝吸杂能够有效的提高硅片的电学性能，实验优化后的铝吸杂温度是 800。 关键词：多晶硅；退火；铝吸杂；少子寿命 中图分类号：TN304.1;TK511 Effects of annealing and Al gettering on properties of solar multicrystalline silicon Zhang Junfeng1,3, Chen Xiuhua2, Ma Wenhui1,3, Zhang Cong1,3, Wei Kuixian1,3 (1. National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, China; 2. School of Physical Science and Technology, Yunnan University, Kunming 650091，China; 3. Engineering Research Center for Silicon Metallurgy and Materials of Yunnan Provincial Universities, Kunming University of Science and Technology, Kunming 650093, China) Abstract: Annealing and Al gettering were performed on upgraded metallurgical grade multicrystalline silicon (UMG multi-Si) wafers with a purity of 99.999%. The dislocation and grain boundaries of samples were characterized by optical microscopy and electron back scattering diffraction (EBSD), respectively. The minority carrier lifetime and resistivity of the Si wafers were measured using microwave photoconductance decay and four-point probe techniques, respectively. The results show that the number of dislocations in Si wafers reduced obviously after annealing and Al gettering for 2 hours at 600～1100°C. The proportion of Σ3 grain boundary increases. But the minority carrier lifetime and resistivity of the Si wafers after annealing decreases. However, the minority carrier lifetime and resistivity of the Si wafers after Al gettering increases firstly and then decreases with increasing of the annealing temperatu