Industrial Production of Perovskite-Silicon Tandem Solar Cells: The Characterization Challenge

Characterization of perovskite–silicon (Pero/Si) tandem solar cells in an industrial environment is hampered by several challenges. First, the monolithic series connection of the two subcells and the fact that the entire stack shares only two electrical terminals make it impossible to probe each subcell independently. Second, the perovskite absorber's metastability—most notably ion migration—introduces additional, often slow, time-dependent effects. Together with the industry's requirement for high throughput, these factors complicate accurate, high-speed characterization. In this work we propose a concept to acquire I–V data for tandem solar cells from light-emitting diode (LED)-based solar simulators, where we acquire an approximation of the external quantum efficiency from LED-based measurements before conducting an I–V measurement with an adjusted LED illumination spectrum. We present results on a reference III/V and different Pero/Si solar cells. We model ion migration in perovskite subcells, which allows for assessing preconditioning and transient effects in I–V cell measurements. We recommend a short preconditioning under light to stabilize the scan time dependence and show the potential for transfer between industrial and lab conditions. Finally, we showcase concepts of camera-based luminescence measurements for inline analysis. Specifically, we show a line-scan photoluminescence approach, a fast electroluminescence (EL) imaging approach based on parallel data acquisition with two cameras, and an EL concept based on the application of one RGB camera.