Fig. 2: Ultrafast transient reflectivity measurements.
From: Mahan excitons in room-temperature methylammonium lead bromide perovskites
a Color-coded map of ΔR∕R as a function of probe photon energy and time delay between pump and probe. The pump photon energy is 3.10 eV and the estimated carrier density is n = 5 × 1018 cm−3. The time resolution is 50 fs. b, c ΔR∕R transient spectra in the temporal windows b from −100 fs to 500 fs and c from 500 fs to 8 ps.
