基于物理冶金多晶硅太阳电池的磷扩散工艺

Phosphorus diffusion process based on metallurgical grade silicon solar cells

作为制备晶体硅太阳电池的核心技术,扩散后方块电阻的均匀性显得非常重要。通过对现有晶体硅太阳电池扩散工艺进行改进,提出一种间断性变温磷扩散工艺。此工艺应用于物理冶金多晶硅太阳电池制备中,所形成的p-n结表面杂质浓度低,杂质分布均匀,提高了硅片少子寿命和方块电阻的均匀性,有利于电子的收集,减少了太阳电池因复合造成的效率损失,从而提高电池片最终光电转换效率。与现有工艺相比,减少了三氯氧磷、干氧的使用量,缩短了工艺时间,节约了生产成本。

Abstract： As the key production process of the crystalline silicon solar cell, the square resistance＇ s uniformity after diffusion plays a very important role. Through the improvement of existing phosphorus diffusion process, an intermittent variable temperature phosphorus diffusion process was presented. When the process was applied in the preparation of physical metallurgy polycrystalline silicon solar cells, p-n junction with low and uniform impurity concentration surface was formed. It improves the uniformity of the square resistance and the minority carrier lifetime of the silicon wafer. It is conducive to the collection of electrons and reducing the efficiency loss of solar cells that caused by the carrier＇ s composite, thereby the eventually conversion efficiency of the cells is improved. Compared with the current technology, the new process can also save the production cost, reduce the consumption of POCI3 and O2, shorten the process time.