Fast Luminescence Imaging of Multijunction Solar Cells with a Single Shot

Monolithic perovskite silicon tandem solar cells reach impressively high efficiencies. However, fast and spatially resolved measurement methods for quality control are required for the industrial production. In this work, we present a novel approach for separating luminescence images of tandem and triple-junction solar cells using a color camera with a Bayer matrix to simultaneously acquire luminescence images of up to three subcells in a multijunction device. The method relies on the spectral variation of the camera's different color channels’ spectral response or quantum efficiency, enabling clear separation of the subcells’ signals. We outline the underlying mathematical equations and determine the quantum efficiency of the camera system. Through example measurements on perovskite silicon tandem solar cells, we demonstrate the effectiveness of our method compared with reference measurements. The results reveal a distinct separation of luminescence signals, highlighting differences in sharpness and contrast between the subcells. This technique not only offers a cost-effective solution for inline characterization of multijunction solar cells but is also transferable to other solar cell types. Our findings open new avenues for optimizing the performance of tandem solar cells and contribute to the successful commercialization of this technology.