Formation of Various Pyramidal Structures on Monocrystalline Silicon Surface and Their Influence on the Solar Cells

Texturization is a useful method to enhance the optical absorption of monocrystalline silicon wafers by light-trapping effect in solar cell processing. In present study, a series of textured wafers with various pyramid sizes ranging from 200 nm to 10 mu m were fabricated by modified wet-chemical method and characterized. The results show that there is little difference in the reflectance with the pyramid sizes from 1 to 10 mu m, which is consistent with the ray-tracing simulation results. However, the light-trapping function of the 200 nm sample below the geometrical optics limit is much weaker. The solar cells fabricated from the 1 mu m samples own the highest power conversion efficiency of 18.17% due to a better coverage of metal finger lines than the larger ones, and the 200 nm samples have the lowest efficiency of 10.53%.