Low-reflective Surface Texturing for Large Area Multicrystalline Silicon Using NaOH-NaClO Solution

摘要

Multicrystalline silicon surface texturing using the mixed etching solution of the sodium hydroxide (NaOH) and of the sodium hypochlorite (NaClO) has been investigated. The reaction rate during the texturing process is easier to control due to the presence of NaOCl as an oxidizing agent in NaOH solution. The advantage of this etching is that the uniform mc-Si surface texturing with a low step height and less grain boundary delineation can be obtained. The Mc-Si surface after NaOH-NaOCl mixed etching with the 1:4 ratio in the case of 20% NaOH has the optimum light trapping effect. In the case of the optimum etching condition, the average reflectivity for the textured surface of a large area (156×156 mm~2) mc-Si can be reduced to less than 10%.