Ultrafast Carrier Cooling in Led Halide Perovskite Solar Cells

Delocalized band states in photovoltaic materials act as the gateway for charge separation, and thorough study of such hot-state charge delocalization can be achieved by IR photon excitation. Here, we study the processes of ultrafast carrier cooling in such materials by three pulse pump-push-probe technique. The materials under study reveal subpicosecond cooling times, dependent on the push intensity. We associate the slope in the cooling time with the effect of phonon bottleneck.