Inline millisecond subcell current metrology for perovskite/silicon tandem solar cells

Monolithic perovskite/silicon tandem solar cells require fast, inline-capable metrology to control subcell current matching during production. Here, we present an electrical transient method that extracts both subcell photocurrents from a single measurement on a finished tandem within milliseconds, without spectral modification. The approach exploits the silicon subcell’s capacitive charge reservoir and millisecond carrier lifetime—a brief forward pre-bias charges the reservoir, and a voltage step triggers a current overshoot. This overshoot reveals a perovskite-limited plateau followed by steady-state silicon limitation upon reservoir depletion, yielding both currents from one transient. An analytical model and Sentaurus TCAD simulations quantitatively predict the transient behavior. Validation on laboratory-scale and full-size industrial cells shows excellent agreement with spectrometric characterization while reducing measurement time from hours to milliseconds. The method integrates into standard high-throughput inline reverse j - V routines, minimally perturbs the perovskite subcell, and extends to other multijunction architectures combining direct and indirect semiconductors.