Development of the laser method of multicrystalline silicon surface texturization

Purpose: The aim of the paper is to demonstrate a laser method of multicrystalline silicon texturization. This means creating a roughened surface so that incident light may have a larger probability of being adsorbed into the solar cell. It was demonstrated, that laser processing is very promising technique for texturing multicrystalline silicon independent on crystallographic orientation of grains compared to conventional texturing methods. Design/methodology/approach: The topography of laser textured surfaces were investigated using ZEISS SUPRA 25 scanning electron microscope and LSM 5 Pascal ZEISS confocal laser scanning microscope. The reflectance of produced textures was measured by Perkin-Elmer Lambda spectrophotometer with an integrating sphere. Electrical parameters of manufactured solar cells were characterized by measurements of I-V illuminated characteristics under standard AM 1.5 radiation. Findings: The texturing of multicrystalline silicon surface using Nd:YAG laser makes it possible to increase absorption of the incident solar radiation. Laser processing is a promising method for texturization of multicrystalline silicon compared to conventional texturing methods applied in used technology of solar cells. Research limitations/implications: Laser processing introduce into the bulk of material some unwanted effects, having detrimental influence on the main parameters of processed silicon wafers. Solar cells manufactured from laser-textured multicrystalline silicon wafers demonstrate worse electrical performance than cells manufactured from the non-textured wafers after saw damage removal as well as wafers textured by etching in alkaline solutions. Chemical etching by means of potassium alkali made it possible to increase cell efficiency. Originality/value: Laser texturing has been shown to have great potential as far as its implementatnion into industrial manufacturing process of solar cell is concerned.