On the Robustness of the Determination of Metal-Induced Recombination from Photoluminescence Images on Solar Cells

The robustness of a recently developed method to obtain the recombination current-density (J0,met) under the front metallization fingers of silicon solar cells is investigated. This method requires a voltage-calibrated photoluminescence (PL) imaging setup and can be applied on finished solar cells without any dedicated sample preparation. The Fourier-transform photoluminescence method (FTPL) compares the Fourier spectrum of a PL image with an analytical model to deduce J0,met. It is demonstrated here, from sensitivity analysis, repeated measurements, and case studies, that the method allows to differentiate groups of solar cells having undergone different metallization conditions. Moreover, the comparison of the FTPL method with I-V measurements and with the area-weighted approach for the J0,met determination shows similar results. Finally, using Quokka modeling, some limitations of the method are identified, and opportunities for improvement are proposed to further enhance this characterization technique. The Fourier-transform photoluminescence method (FTPL) compares the Fourier spectrum of a PL image with an analytical model to deduce the metal-induced recombination in a finished solar cell. From sensitivity analysis, case studies, and comparison with other characterization techniques, the robustness of this method is attested.image & COPY; 2023 WILEY-VCH GmbH