Novel chemical texturizing process in Boron–doped As-cut multi-crystalline silicon wafer for increasing the optical properties

Abstract

The aim of this paper, the improvement of optical properties of as-cut boron doped p-type multi-crystalline silicon (mc-Silicon) wafer grains obtained by chemical texturization is presented. mc-Silicon wafer gives lower reflectance is one of the important parameters for improving solar cell efficiency and it can be obtained by the optimized texturizing conditions. In this work, we have carried out different types of chemical etchants in the same ratios for the texturizing process. Here, we have carried out HF + HNO3 + KMnO4 = 2.5:1:0.2M (set-1), HF + HNO3 + K2Cr2O7 = 2.5:1:0.2 M (set-2) and HF + HNO3 + IPA =2.5:1:0.2M (set-3) for the individual etchant etching time duration is 2 minutes, 5 minutes and 7 minutes. The mc-Silicon wafer grains were analyzed by the optical microscope, UV- visible, X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Thickness profilometer, and Fourier transforms infrared (FTIR) spectroscopy for before and after texturizing. The set-1 with a 2-minutes etched wafer gives better results as the lower reflectivity value is below 12.5%, lower surface roughness, lower oxidation, and better surface contained.The same orientation of the grains were used as indicated by XRD results. The sheet resistance of the mc-Silicon wafer grains were calculated by the four-probe method.