表面钝化对多晶硅绒面形貌的影响

多晶硅表面制绒技术是太阳能光伏产业亟待突破的一个关键技术.本文根据多晶硅强酸制绒的基本原理,提出了表面活性剂钝化多晶硅表面以降低硅原子与酸反应速度从而改善多晶硅绒面形貌的方法.实验研究了不同含量的添加剂对酸液刻蚀多晶硅绒面形貌的影响,用扫描电镜观察对应的绒面结构,用积分反射仪测量其绒面的表面反射率.实验结果表明:加入活性剂后酸液能使多晶硅表面陷阱坑分布更加均匀,并且能有效消除产生漏电流的缺陷性深沟槽,样品表面反射率比较低,其表面反射率降低到21.5%.与传统酸液腐蚀的多晶硅绒面结构相比,陷阱坑密度明显增加,这种方法在多晶硅太阳电池的生产中是有价值的.

Influence of Multi-crystalline Silicon Surfaces Passivation on Pit Topography of Textured Surface

The surface texturing of multi-crystalline silicon is a technology that needs to be broken through. For the improvement of pit-trap shape on mc-Si surface, a new method is presented that the passiviation of Si surface is done to reduce the acid reaction velocity. A series of experiments are carried out in which mc-Si is textured in the acid solution containing different content of additives under the same technology parameters. Samples' structure is observed using scanning electron microscope, and the reflectance spectrum is measured by spectrophotometer. The SEM of experimental sample's surface illustrates that the textured surface is full of a lot of pit trap with the good light trapping effect. Moreover, the deep ditch like valley, which increases the leakage current of mc-Si solar cells and reduces the conversion efficiency, is not found in the surface. This method is valuable for the improvement of solar cell efficiency.