Investigation of the role of Saw damage in Silver catalyzed Metal Assisted Chemical Etching on Multicrystalline Silicon for Solar cell Application

This work investigates how the saw damage from different processes affected the Silver-catalyzed Metal Assisted Chemical Etching. Multicrystalline silicon ingot was grown from a 15 kg Directional Solidification (DS) furnace. The wafers were extricated from silicon brick by using the blade or diamond wire cutting machine which leaves the saw damage in the substrate of the wafer. Surface texturization process is required to reduce the reflectance of the wafer and to trap more photons on the surface. Silver-catalyzed Metal Assisted Chemical Etching was deployed to texture the surface of the silicon wafer. Five Mc-Si wafers were prepared through blade cut, diamond wire cut, lapping, mechanical polishing and chemical polishing. The surface of those wafers was textured using Silver-catalyzed Metal Assisted Chemical Etching. The preliminary studies like weight measurement, thickness calculations, lifetime measurement and resistivity are made. From the preliminary studies, it is confirmed that the etching rate is directly proportional to the roughness of the surface. All the wafers are subjected to SEM, Optical Microscopy and UV-Vis-NIR analysis. It is concluded that the saw damage affected the proper metal coating at the surface. The nanostructures are found in mirror-like polished wafers which produce the lowest weighted average reflection of 2.573%. From the results obtained from the characterizations, the simulations were done to examine the efficiency of the solar cell made from differently processed silicon wafers.