Ag and Cu metal-assisted chemical etching for diamond-wire-sawn single-crystalline silicon solar cell

Abstract In the present study, Ag and Cu metal-assisted chemical etching (MACE) technique was used for etching single-crystalline silicon at 15–25 °C, followed by post-processing with the HF/HNO3/H2O solution. Further, the relationship between the shape of the cross-section of the pore and the quality of passivation was deciphered. The parameters Jo1, minority carrier lifetime, and surface recombination velocity were measured, and the correlation between these three parameters and the open-circuit voltage (Voc) value was determined for all solar cells. The changes in the reflectance, solar flux density, and external quantum efficiency with changing wavelength were analyzed, and the relationship of these changes with short-circuit current density was determined. The Voc of all Ag-MACE solar cells is greater than that of all Cu-MACE solar cells, although the efficiency of almost all Cu-MACE solar cells is higher than that of the Ag-MACE solar cells. Furthermore, the electroluminescence image, the adhesion between the silver electrode and the pore, the quality of the aluminum back surface field, the metal residues on the surface, and the bulk of the wafer were systematically investigated. The best solar cell efficiency obtained for Ag-MACE and Cu-MACE PERC structures was 18.68% and 19.32%, respectively.