Time-resolved fluorescence imaging as a self-consistent characterization method for photovoltaic materials

Photoluminescence recording and analysis is a well-known and powerful characterization tool for semiconductors. Here, we show how our time-resolved fluorescence imaging set-up (TR-FLIM) constitute a self-consistent characterization method for transport properties inside photovoltaic absorbers and devices. We apply this method to both homogeneous GaAs solar cell, featuring enhanced lateral diffusion, and slowly diffusive perovskite absorbers. Relying us on models including in-depth or lateral temporal diffusion and recombination properties, we could fit key optoelectronic properties such as the diffusion length and lifetime of charge carriers, as well as the recombination velocities at critical interfaces.