Information on Recombination Under Front Fingers Based on Fourier Analysis of Photoluminescence Images

The extraction of the implied open-circuit voltage (iV
_OC
) and saturation current density under the metal fingers (j
_0met
) using a single photoluminescence (PL) image is demonstrated in this article. The method employed to derive these parameters is based on an analytical modeling of the local p-n-junction voltage between the metallization fingers and on the analysis of the p-n-junction voltage variations obtained using a calibrated PL image. The image is analyzed in the Fourier space; taking advantage of the periodicity of the metal grid, the relevant information is extracted from the first two Fourier peaks. The (iV
_OC
) and (j
_0met
) are calculated from the peaks intensities. This method is compared with one that uses two PL images. Both methods agree within their uncertainty (±200 fA/cm
²
for j
_0met
). The main advantage of the method developed in this article is that only one image is required.